JP4331885B2 - Mortar component installation tool - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an installation tool for acetabular components used for hip replacement.
[0002]
[Prior art]
Artificial hip replacement is a means for recovering hip function that has lost normal function due to an accident or illness.
[0003]
When performing such an operation, it is necessary to fix the shell of the acetabular component at an appropriate installation angle. If this installation angle is poor, it may cause complications such as post-operative dislocation.
[0004]
In general, an appropriate installation angle is suitably an inclination angle of 40 to 45 ° and a front opening angle of about 20 °.
[0005]
7 and 8 show a conventional acetabular component installation tool C. FIG. In this installation tool C, two types of handles A and B are fixed to a main shaft E provided with a male screw portion D for allowing the shell F of the acetabular component to be freely held at the tip. One of these handles (handle B) is for adjusting the installation angle to the inclination angle, and the other handle A is for adjusting the installation angle to the front opening angle.
[0006]
The handle B has a handle B1 fixed at an inclination of 45 to 50 ° with respect to the main axis E, and the handle B has a handle B with respect to the body axis as shown in FIG. By adjusting B1 in the direction of 90 °, the tilt angle of 40 to 45 ° can be secured.
[0007]
In addition, the handle A is fixed to the handle B with a tilt of 20 ° with respect to the main axis E on the surface orthogonal to the handle B1 of the handle B. As shown in FIG. 10, the front opening angle of 20 ° can be secured by aligning the handle A1 of the handle A in a parallel direction with respect to the body axis.
[0008]
In this way, with the installation tool C, the installation tool C is removed from the shell F in a state where the shell F of the acetabular component is adjusted to a predetermined installation angle, and the liner of the acetabular component is fixed to the shell F according to a predetermined method. To do.
[0009]
[Problems to be solved by the invention]
According to the above prior art, in many cases, it was possible to perform appropriate installation, but in some cases, dislocation may occur after surgery even though the acetabular component was installed at a predetermined installation angle. there were.
[0010]
The reason for this is that the installation angle tends to cause dislocation of the artificial hip joint instead of the installation angle of the femoral component.
[0011]
In other words, in order to completely prevent the dislocation of the artificial hip joint, it is necessary to take into account the installation angle of each femoral component for each case. This is because the acetabular component was to be installed only at an angle.
[0012]
Therefore, in view of such a situation, the present invention confirms an appropriate installation angle of the acetabular component by trial during artificial hip joint replacement in order to prevent postoperative dislocation, and installs the acetabular component with the installation angle. The purpose is to be able to.
[0013]
[Means for Solving the Problems]
In order to solve the above problems, an installation instrument of the present invention comprises a main shaft provided with holding means for detachably holding the acetabular trial and the shell of the acetabular component at the tip, and a wire guide member detachable from the main shaft. provided, the said wire guide member, and wherein the obtaining Bei substantially parallel as possible through the word ear hole in the axial direction of the main axis.
[0014]
According to such a configuration, an appropriate installation angle of the acetabular component can be confirmed by trial during the hip replacement, and the acetabular component can be installed at the installation angle.
[0015]
That is, with the acetabular trial held at the tip of the main spindle, place the acetabular trial on the acetabulum, align the acetabular trial at a predetermined installation angle using the above-described conventional handle, etc. The acetabular trial is fixed to the bone using fixing means.
In this state, a wire (for example, Kirschner wire : K wire) is inserted into the hole of the wire guide member attached to the main shaft, and the tip of the K wire is inserted into the bone.
Then, after the insertion of the K wire, the installation tool is removed from the acetabular traal.
At this time, only the installation tool is removed leaving the K wire.
[0016]
Thereafter, a trial on the femur side is installed, and reduction is performed using the trial and the acetabular trial to confirm the presence or absence of dislocation.
[0017]
When dislocation occurs, after confirming the direction of dislocation, installation of the acetabular trial, insertion of the K wire into the bone, and reduction are performed again according to the procedure described above. This is repeated until it can be confirmed that dislocation does not occur.
[0018]
When it is finally confirmed that dislocation does not occur, the acetabular trial is removed leaving the K wire, and the shell of the acetabular component is installed. The procedure for installing the shell is as follows.
[0019]
First, the shell of the acetabular component is fixed to the tip of the main shaft by the holding means, and the wire guide member is removed from the main shaft. The removed wire guide member is fitted to the K wire inserted into the bone. By placing the shell of the acetabular component together with the main shaft on the acetabulum and attaching a wire guide member to the main shaft, the installation position and installation angle of the acetabular trial are reproduced. In this state, the shell of the acetabular component is fixed, and finally the installation tool and the K-wire are removed.
[0020]
In addition, when removing an installation tool from a acetabular trial, since the acetabular trial is not hold | maintained at the front-end | tip of a main axis | shaft, a wire guide member can be removed from a K wire, with the wire guide member attached to a main axis | shaft. On the other hand, when installing the shell of the acetabular component, since the shell is held at the tip of the main shaft of the installation tool, the wire guide member is attached to the main shaft while the wire guide member is attached to the main shaft. Attaching to the wire is virtually impossible, as the tissue around the acetabulum becomes an obstacle. Therefore, in the present invention, the wire guide member is detachable from the main shaft.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0022]
1 to 6, 1 is an installation tool, 2 is a main shaft, 3 is a male screw portion as a holding means, 4 is a wire guide member, 5 is a hole for inserting a K wire 6, 7 is a acetabular trial, and 8 is It is the shell of the acetabular component.
[0023]
The installation tool 1 is made of a metal material such as stainless steel which is not easily rusted and has high strength.
[0024]
As shown in the exploded perspective view of FIG. 1, the main shaft 2 includes an outer cylinder 21 and a shaft body 22 inserted through the outer cylinder 21. The shaft body 22 is formed with a male screw portion 3 at a tip portion that can project from the outer cylinder 21, and a rear end thereof is a large diameter portion 23.
[0025]
The male screw part 3 holds a mortar trial 7 and a shell 8 of a mortar component, which will be described later, in a detachable manner.
[0026]
Further, a T-shaped handle 9 is provided on the main shaft 2 so as to protrude from the axial central portion of the outer cylinder 21 at a predetermined angle with respect to the axial direction of the main shaft 2. Further, the handle 91 of the T-shaped handle 9 is provided with a front opening angle adjusting rod 10 in the orthogonal direction.
The T-shaped handle 9 is fixed with an inclination of 45 to 50 ° with respect to the main shaft 2, and the handle 91 is set in a 90 ° direction with respect to the body axis in a state where the patient is in a lateral position. The inclination angle can be set to 40 to 45 °.
Further, the front opening angle adjusting rod 10 can be moved stepwise by 5 ° in the range of 0 to 30 ° to the left and right with respect to the main shaft 2 on the surface perpendicular to the handle 91 of the T-shaped handle 9. It is like that.
[0027]
That is, the front opening adjusting rod 10 has a base portion 11 at one end, and the base portion 11 is rotatable about the handle 91 of the T-shaped handle 9. One protrusion (not shown) is formed on the upper surface of the base 11. On the other hand, the handle 91 of the T-shaped handle 9 is provided with an upper plate 92 facing the base 11, and the upper plate 92 has a plurality of small holes 93 that can be fitted to the protrusions in the rotation direction. It is formed at intervals of 5 °. With this configuration, as described above, the front opening angle adjusting rod 10 can be moved stepwise in the range of 0 to 30 degrees to the left and right of the main shaft 2 every 5 degrees.
[0028]
A wire guide member 4 is detachably attached to the main shaft 2.
[0029]
The wire guide member 4 includes a fitting portion 41 with the main shaft 2, a K wire guide portion 42, and a connecting portion 43 between the fitting portion 41 and the guide portion 42. The fitting portion 41 has a semi-cylindrical shape and can be attached to the outer peripheral surface of the outer cylinder 21 of the main shaft 2. The guide portion 42 is configured to carry a plurality of small tubes 44 and to insert the K wire 6 through the holes 5 of the small tubes 44.
[0030]
Thus, the advantage of providing a plurality of holes 5 through which the K wire 6 is inserted is that the installation accuracy of the shell 8 of the acetabular component can be improved.
[0031]
That is, when only one K wire 6 is used, the installation instrument 1 can be swung in the rotation direction around the K wire 6, whereas the installation accuracy may be reduced. Such a problem can be prevented when a plurality of K wires 6 are used. Further, when a plurality of K wires 6 are used, the substantial strength of the K wires 6 is increased, so that the bending due to stress at the time of shell installation is reduced. As a result, the installation accuracy can be increased.
[0032]
The advantage of using the small tube 44 for the guide portion 42 is also the same. By increasing the holding length of the K wire 6, the substantial strength of the K wire 6 is enhanced and the installation accuracy of the shell 8 is increased. Can do.
[0033]
The acetabular trial 7 has substantially the same outer shape as the acetabular component that is finally installed on the acetabulum. That is, the hemispherical outer surface has substantially the same shape as the hemispherical outer surface of the shell 8 of the acetabular component. The acetabular trial 7 includes a concave portion 71 having a hemispherical shape. The recess 71 has substantially the same shape as the head fitting hole in the liner of the acetabular component.
[0034]
A screw hole 72 into which the male screw portion 3 of the installation tool 1 is screwed is formed at the bottom of the recess 71 so that the acetabular trial 7 can be held at the tip of the installation tool 1.
[0035]
The acetabular trial 7 is provided with a plurality of through-holes 74 for pin fixing at a peripheral edge 73 located around the opening of the recess 71.
[0036]
Next, the installation procedure of the mortar component shell (hereinafter abbreviated as “shell”) 8 using the installation tool 1 will be described.
(Installation of acetabular trial and K-wire)
As shown in FIG. 2, the acetabular trial 7 is placed on the acetabulum while the acetabular trial 7 is held at the tip of the installation instrument 1, and a predetermined shape is obtained using the T-shaped handle 9 and the front opening angle adjusting rod 10. Match the acetabular trial 7 to the installation angle.
[0037]
The acetabular trial 7 is held by screwing the male thread portion 3 provided at the tip of the shaft body 22 with the screw hole 72 of the acetabular trial 7. The male screw portion 3 is rotated by rotating the large diameter portion 23 of the shaft body 22. At this time, the acetabular trial 7 is held by hand for screwing.
[0038]
Next, the acetabular trial 7 is fixed to the bone using a fixing means such as a pin P. In this state, the K wire 6 is inserted into the hole 5 of the wire guide member 4 attached to the main shaft 2, and the tip of the K wire 6 is inserted into the bone.
(Temporary removal and reduction of installation equipment)
Subsequently, after the insertion of the K wire 6, the installation tool 1 is removed from the K wire 6 with the installation tool 1 removed from the acetabular trial 7, and the acetabular trial 7 and the K wire 6 are attached as shown in FIG. 3. Leave it as it is. At this time, the installation tool 1 is pulled out in a direction parallel to the K wire 6.
[0039]
Thereafter, a trial on the femur side is installed, and reduction is performed using the trial and the acetabular trial 7 to confirm whether or not a dislocation has occurred.
[0040]
When dislocation occurs, after confirming the direction of dislocation, installation of the acetabular trial 7, insertion of the K wire 6 into the bone, and reduction are performed again according to the above procedure. This is repeated until it can be confirmed that dislocation does not occur.
(Installation of shell)
When it is finally confirmed that dislocation does not occur, the mortar cover trial 7 is further removed from the state of FIG. The procedure for installing the shell 8 is as follows.
[0041]
First, as shown in FIG. 5, the holding means 3 fixes the shell 8 to the tip of the main shaft 2. The shell 8 is held by screwing a male screw portion 3 provided at the tip of the shaft body 22 and a screw hole 81 formed in the bottom portion of the shell 8. Further, the wire guide member 4 is detached from the main shaft 2, and the removed wire guide member 4 is fitted to a K wire 6 inserted into a bone as shown in FIG.
[0042]
The shell 8 is placed on the acetabulum together with the main shaft 2, and the wire guide member 4 is attached to the main shaft 2 as shown in FIG. At this time, the installation position and the installation angle of the acetabular trial 7 are reproduced by the K wire 6. In this state, the shell 8 is fixed by a predetermined method, and the installation tool 1 and the K wire 6 are removed. Finally, a mortar component liner is attached to the fixed shell 8 by a predetermined method.
[0043]
As mentioned above, although embodiment of this invention was illustrated, this invention is not limited to the said embodiment. For example, the holding means may be a fitting form using a ball plunger in addition to the male screw portion 3. In short, any form can be employed without departing from the object of the invention.
[0044]
【The invention's effect】
As described above, according to the installation tool of the present invention, the tip is provided with a main shaft provided with holding means for detachably holding the acetabular trial, and a hole that is detachable from the main shaft and into which the Kirschner wire can be inserted. With the configuration comprising the wire guide member, it is possible to confirm an appropriate installation angle of the acetabular component by trial during the hip replacement and to install the acetabular component at the installation angle. Therefore, dislocation of the artificial hip joint after the operation can be prevented.
[0045]
Further, in the configuration of the present invention, when a plurality of holes through which the K wire is inserted are provided, the installation tool can be prevented from swinging in the rotation direction around the K wire. Since the curvature of the wire can be reduced, the installation accuracy can be increased. Thereby, the further dislocation prevention effect of the postoperative hip prosthesis can be acquired.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view of an installation tool and a mortar trial of the present invention.
FIG. 2 is an assembly diagram of the installation instrument and acetabular trial of FIG. 1;
FIG. 3 is a perspective view showing a state in which the acetabular trial is installed on the acetabulum.
FIG. 4 is a perspective view of a state in which a wire guide member removed from a main shaft is combined with a K wire.
FIG. 5 is an assembly view of the shell of the acetabular component and the installation tool.
6 is an assembly view in which the wire guide member of FIG. 4 is mounted on the installation tool of FIG. 5;
FIG. 7 is a front view of a conventional installation tool.
8 is a top view of the installation tool of FIG.
9 is a diagram for explaining a method of using the installation tool of FIG.
10 is a view for explaining a method of using the installation tool of FIG. 7;
[Explanation of symbols]
1 Installation tool 2 Spindle 3 Male thread part (holding means)
4 wire guide member 5 hole 6 K wire 7 acetabular trial 8 acetabular component shell 9 T-shaped handle 10 front opening angle adjusting rod P pin

Claims (2)

A main shaft provided with holding means for detachably holding the shell of the acetabular trial and the acetabular component at the tip, and a wire guide member detachable from the main shaft ;
The said wire guide member, characterized in that Ru comprising substantially parallel as possible through the word ear hole in the axial direction of the spindle, fixture of acetabular components. The wire guide member, characterized in that it comprises on the verge ear to be inserted a plurality of holes, fixture of acetabular component of claim 1, wherein.

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