Acetabular cup removal device for artificial hip joints

Abstract

The acetabular cup removal device for artificial hip joints according to an embodiment of the present invention includes a main shaft and a cutter unit that cuts the acetabular portion while rotating around the main shaft. The cutter unit includes a cutter tilt unit that can be tilted along the acetabular portion around a virtual tilt axis, a cutter mounting unit that is slidably coupled to the cutter tilt unit in a direction approaching or moving away from the virtual tilt axis, and a cutter detachably mounted on the cutter mounting unit. The cutter tilt unit includes a first through hole penetrating along the virtual tilt axis, a connecting bar having both ends fixed to the cutter mounting unit, and a leaf spring fixed to both ends of the connecting bar and having a central portion between both ends.

Description

Technical Field

[0001] The present invention relates to a device for removing a wide acetabular cup for an artificial hip joint.

Background Art

[0002] Generally, an artificial hip joint is a substitute used for the purpose of replacing a hip joint when its function is impaired. It is transplanted to the site where the hip joint was present and can maintain normal activities.

[0003] Such an artificial hip joint is divided into a hemispherical acetabular cup having a liner that serves as a bearing and inserted into the acetabulum of the pelvis, a stem attached to the femur, and a hemispherical head provided at the end of the stem to replace the femoral head and inserted into the acetabular cup.

[0004] Therefore, patients who do not function normally due to sequelae of arthritis, dysplasia, trauma or infection and feel pain in the hip joint can restore the joint's motor function and remove the pain by replacing the painful hip joint with the above artificial hip joint.

[0005] On the other hand, such an artificial hip joint wears out with long-term use. In particular, the acetabular cup that rubs against the head has a high wear rate due to continuous joint use. When the wear progresses, osteolysis may occur around the acetabulum of the pelvis where the acetabular cup is inserted. For this reason, technologies for removing an already inserted acetabular cup from the acetabulum of the pelvis have been continuously developed.

[0006] In connection with this, the applicant has developed an acetabular cup removal device for an artificial hip joint, as disclosed in Korean Registered Patent No. 10-2103774, as shown in Figures 1 to 4. For reference, Figures 1 to 4 correspond to Figures 1, 4, 3, and 7 of the aforementioned Korean Registered Patent, respectively, and for the sake of explanation, the reference numerals in the drawings are shown as they are without modification. Furthermore, even if the same reference numerals are used in the drawings used in the description of the present invention later, they do not necessarily refer to the same components.

[0007] The conventional acetabular cup removal device 100 removes the acetabular cup from the acetabulum of the pelvis by moving the stepless adjustment unit 140 forward and sequentially moving the cutter 1501 forward (counterclockwise) (see Figure 4). In addition, if the acetabular cup (C) is spherical (shaped like half a sphere cut off), the acetabular cup C can be removed using a cutter 1501 that is suitable for the radius of the acetabular cup (see Figure 5(a)).

[0008] However, when the acetabular cup C is elliptical (shaped like an ellipse cut in half along its minor axis), there was a problem where the cutter 1501 would catch on the outer surface of the acetabular cup C (the part indicated by ★) as it tilted towards the apex O of the acetabular cup along the major axis A of the ellipse during cutting, preventing it from progressing normally, or in severe cases, causing the cutter to break (at 60° rotation in Figure 5(b)). To address this, a cutter with a larger radius could be used, but this would increase bone loss in the patient. [Prior art documents] [Patent Documents]

[0009] [Patent Document 1] Korean Registered Patent Publication No. 10-2103774 [Overview of the Initiative] [Problems that the invention aims to solve]

[0010] The technical problem of the present invention is to solve the problems of the conventional acetabular cup removal device described above, and to provide an acetabular cup removal device for artificial hip joints that can remove the acetabular cup from the acetabulum of the pelvis while smoothly cutting through the outer surface of the acetabular cup without the cutter catching, even when the acetabular cup is oval-shaped as well as circular. [Means for solving the problem]

[0011] To achieve the above objective, the acetabular cup removal device for artificial hip joints according to an embodiment of the present invention includes a main shaft that can be attached to a power tool and rotated by the driving force of the power tool, and a cutter section provided at the front end of the main shaft, which can be moved along the acetabular portion in which the acetabular cup has been implanted, and which cuts the acetabular portion while rotating by the main shaft. The cutter section is a virtual Tilt A cutter section that can be attached along the acetabular portion with respect to the axis, the virtual Tilt The cutter mounting portion includes a cutter mounting portion that is slidably coupled to the cutter tert portion in a direction approaching or moving away from the axis, and a cutter that is detachably attached to the cutter mounting portion. The cutter tert portion includes a first through hole that penetrates along the virtual tert axis, a connecting bar with both ends fixed to the cutter mounting portion, and a leaf spring with both ends fixed to the connecting bar and a center between the ends.

[0012] The main shaft also includes a cylinder portion inserted into the first through-hole, with a second through-hole formed in its longitudinal direction. The connecting bar is positioned within the second through-hole so as to be slidable in a direction toward or away from the virtual tilt axis, and the center of the leaf spring is supported by the inner wall of the second through-hole.

[0013] Furthermore, the second through-hole has a circular cross-section, and the connecting bar has an arc shape in which a portion of its circumference has the same radius of curvature as the second through-hole, allowing it to make surface contact with the second through-hole.

[0014] Furthermore, the remaining portion of the connecting bar, excluding the aforementioned part, does not come into contact with the second through-hole.

[0015] Furthermore, the cutter mounting portion includes a cutter mounting portion body having a third through hole into which the connecting bar is inserted. The connecting bar does not rotate relative to the cutter mounting portion body within the third through hole, and the cutter mounting portion Tilt Sometimes linked Tilt It will be done.

[0016] The other portion of the connecting bar has three sides that are connected at right angles to each other, and the third through hole forms a rectangular cross-section.

[0017] Furthermore, the cutter terting portion further includes a cover that covers the cutter mounting portion body and is fixed to the opposing surface of the cutter terting portion.

[0018] A groove corresponding to the contour of the cutter mounting part body is formed on the inner surface of the cover, and a gap is formed between the upper end of the cutter mounting part body and the upper end of the groove of the cover.

[0019] Furthermore, in the initial state when no external force acts on the leaf spring, a portion of the connecting bar is in contact with the second through hole, and when an external force acts on the leaf spring, the leaf spring is compressed, and a portion of the connecting bar is separated from the second through hole.

[0020] Furthermore, the cover is secured to the connecting bar by fasteners so as not to move relative to the opposing surface of the cutter section. [Effects of the Invention]

[0021] The acetabular cup removal device for artificial hip joints according to the embodiment of the present invention having the configuration described above can have the following effects.

[0022] According to an embodiment of the present invention, different from the prior art, even in the case of an oval acetabular cup, the cutter can tilt to the apex of the acetabular cup while smoothly moving along the surface of the acetabular cup, so that the acetabular cup can be easily removed from the acetabulum of the pelvis.

[0023] Note that the effects of the present invention are not limited to this, and other effects derived from the configuration of the present invention described later are also included.

Brief Description of the Drawings

[0024] [Figure 1] FIG. 1 shows a conventional acetabular cup removing device for artificial hip joints. [Figure 2] FIG. 2 shows a conventional acetabular cup removing device for artificial hip joints. [Figure 3] FIG. 3 shows a conventional acetabular cup removing device for artificial hip joints. [Figure 4] FIG. 4 shows a conventional acetabular cup removing device for artificial hip joints. [Figure 5] FIG. 5 is a schematic diagram showing the operation of the conventional acetabular cup removing device for artificial hip joints of FIG. 1. [Figure 6] FIG. 6 shows an acetabular cup removing device for artificial hip joints according to an embodiment of the present invention. [Figure 7] FIG. 7 shows the main configuration of the cutter part of the acetabular cup removing device for artificial hip joints of FIG. 6. [Figure 8] FIG. ८ shows a state where the cover is separated in FIG. ७. [Figure 9] FIG. ९ shows a state where the cutter mounting part is removed in FIG. ७. [Figure 10] FIG. १० is a cross-sectional view taken along the A-A direction of FIG. ७. [Figure 11] FIG. ११ shows the coupling state of the connecting bar and the leaf spring in the cutter part of FIG. ६. [Figure 12] FIG. १२ is a schematic diagram showing the restoring force exerted by the leaf spring on the connecting bar in the cutter part of FIG. ६. [Figure 13]Figure 13 shows the cutter section of Figure 6 with the connecting bar connected to the fourth through-hole of the cutter mounting section. [Figure 14] Figure 14 shows the connection between the cylinder section and the cutter attachment section of the acetabular cup removal device for artificial hip joints shown in Figure 6. [Figure 15] Figure 15 is a schematic diagram of the main shaft, including the cylinder portion, of the acetabular cup removal device for artificial hip joints shown in Figure 6. [Figure 16] Figure 16 is a diagram illustrating the operation of the acetabular cup removal device for artificial hip joints shown in Figure 6. [Figure 17] Figure 17 shows a side view (a) and a rear view (b) of the cutter section of the acetabular cup removal device for artificial hip joints shown in Figure 6. [Figure 18] Figure 18 is an exploded perspective view of the main components of the acetabular cup removal device for artificial hip joints shown in Figure 6. [Modes for carrying out the invention]

[0025] Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings, so that those with ordinary skill in the art to which the present invention pertains can easily implement them. However, the present invention can be implemented in a variety of different forms and is not limited to the embodiments described herein.

[0026] Furthermore, the present invention is based on an existing acetabular cup removal device for artificial hip joints invented by the present applicant (Korean Registered Patent No. 10-2103774), and in order to solve the above-mentioned problems, a new configuration related to the connection between the cutter terting part and the cutter mounting part has been derived. For this reason, in order to clarify the essence of the present invention, the following will focus on describing the configuration directly related to the present invention, and the description of other configurations unrelated to the gist of the present invention will be simplified or omitted.

[0027] Furthermore, the terms "first," "second," and "third" used in this embodiment do not indicate order, but are terms used to distinguish between components that share the same name.

[0028] As shown in Figure 6, an acetabular cup removal device for artificial hip joints according to one embodiment of the present invention (hereinafter simply referred to as the "acetabular cup removal device") is an acetabular cup removal device for artificial hip joints that can be attached to a known power tool P equipped with a battery and a motor.

[0029] The acetabular cup removal device of the present invention includes a main shaft 2 and a cutter section 3.

[0030] The main shaft 2 is rotatable by the driving force of the power tool P.

[0031] The cutter section 3 is located at the front end of the main shaft 2 and runs along the acetabular portion where the acetabular cup is implanted. Tilt It is possible to cut the acetabular portion while rotating on the main shaft 2.

[0032] As shown in Figure 7, the cutter section 3 includes a cutter tip section 31, a cutter mounting section 32, and a cutter 33 that is detachably attached to the cutter mounting section 32.

[0034] The cutter tilt section 31 is a virtual Tilt It is possible to tether along the acetabular region with axis A as the center.

[0035] Specifically, as shown in Figures 9, 17, and 18, the cutter section 31 includes a first through hole 311, a fourth through hole 314, a connecting bar 312, and a leaf spring 313.

[0036] The first through-hole 311 is formed by penetrating the cutter tert portion 31 laterally (in the plane of the paper, with reference to a in Figure 17) along a virtual tert axis A. The first through-hole 311 can also have a circular cross-section.

[0037] The fourth through-hole 314 is formed perpendicular to the virtual Teruto axis A, that is, in the vertical direction of the cutter Teruto section 31 (the plane of the paper with reference to b in Figure 17).

[0038] Meanwhile, the main shaft 2 passes through the fourth through-hole 314 of the cutter tert section 31 (see Figure 8). Furthermore, the main shaft 2 includes a cylinder section 22 that is inserted into the first through-hole 311 of the cutter tert section 31 (see Figures 9 and 16).

[0039] The cutter section 31 is rotatable relative to the cylinder section 22.

[0040] The cylinder portion 22 has a second through-hole 21 formed in its longitudinal direction (see Figures 10 and 16). As shown in Figures 8, 12, and 15, the connecting bar 312 is slidable within the second through-hole 21 in directions toward and away from the Tert axis A, passing through the second through-hole 21, and both ends are fixed to the cutter mounting portion 32. Specifically, the connecting bar 312 is slidable in the direction in which the restoring force D of the leaf spring 313 (described later) acts and in the opposite direction due to external forces.

[0041] Furthermore, as shown in Figure 12, the connecting bar 312 has an arc shape in which a portion 3121 of its periphery has the same radius of curvature as the second through-hole 21, and this portion 3121 is capable of surface contact with the second through-hole 21. Moreover, the remaining portion of the connecting bar 312 does not come into contact with the inner wall of the second through-hole 21.

[0042] The leaf spring 313 is fixed to both ends of the connecting bar 312, as shown in Figures 10 and 11, with its central part 3131 supported by the inner wall of the second through hole 21. As is well known, most leaf springs are formed in an elliptical shape using spring steel, which can bend when pressure is applied to one side but returns to its original position after a damping process.

[0043] The cutter mounting portion 32 is connected to the cutter tert portion 31 in a manner that allows it to slide relative to the cutter tert portion 31.

[0044] Specifically, as shown in Figure 13, the cutter mounting section 32 includes a cutter mounting section body 321 having a third through-hole 3211 into which the connecting bar 312 is inserted. Here, the connecting bar 312 is fixed so as not to rotate relative to the third through-hole 3211. To achieve this, for example, as shown in Figure 13, the parts of the connecting bar 312 other than a portion 3121 are composed of three straight sides that are connected at right angles to each other. The third through-hole 3211 has a rectangular cross-section corresponding to this.

[0045] On the other hand, as shown in Figure 8, the cutter terting section 31 may further include a cover 315 that covers the cutter mounting section main body 321 and is fixed to the opposite surface of the cutter terting section 31. The cover 315 is fixed to the opposite surface of the cutter terting section 31 using fasteners 4 so that there is no relative movement. In addition, a groove 3151 corresponding to the contour of the cutter mounting section main body 321 is formed on the inner surface of the cover 315. As a result, when the cutter terting section 31 terminates relative to the cylinder section 22, the cover 315 terminates together with it, causing the cutter mounting section 32 fixed to the connecting bar 312 to terminate.

[0046] On the other hand, as shown in Figures 8 and 10, in the initial state when the connecting bar 312 is not sliding, the cover 315 and the cutter mounting part main body 321 are positioned such that a gap S is formed between the upper end P1 of the cutter mounting part main body 321 and the upper end P2 of the groove 3151 of the cover.

[0047] In the following sections, Figure 10 and Figure 16 With reference to the above, the operation of an acetabular cup removal device for an artificial hip joint according to one embodiment of the present invention having the above-described configuration will be explained.

[0048] If the acetabular cup C is elliptical (shaped as if cut in half along the minor axis of an ellipse), the cutter part 3 is directed toward the apex O of the acetabular cup C in order to remove the acetabular cup C from the acetabulum of the pelvis (Figure 16(See 0° and 30°). At this time, if the cutter part 3 is tilted to a predetermined angle, for example, about 60°, the cutter 33 may catch on the outer surface of the acetabular cup C. In this case, as the cutter part 3 continues to tilt, the contact reaction force between the acetabular cup C and the cutter 33 acts to pull the cutter mounting part 32 in a direction that compresses the leaf spring 313 within the second through hole 21, and as a result, the cutter mounting part 32 can slide in the direction of T in Figure 12b, Figure 13b and Figure 14. At this time, the gap S between the upper end P1 of the cutter mounting part body 321 and the upper end P2 of the groove 3151 of the cover becomes narrower. For reference, Figures 10 and 13a show the initial state in which no external force is acting to slide the cutter mounting part 32.

[0049] Therefore, unlike conventional methods, the cutter 33 moves smoothly along the surface of the acetabular cup C, and the cutter part (cutter) can reach the apex O of the acetabular cup C, making it possible to easily remove the acetabular cup C from the acetabulum of the pelvis while minimizing bone loss in the patient (Figure). 16 (See 90°).

[0050] On the other hand, when the external force acting in the direction of compression of the leaf spring 313 is removed, the restoring force D of the leaf spring 313 causes the cutter mounting portion 32 to slide back to its initial state within the second through hole 21 (see Figure 10). At this time, the gap S between the upper end P1 of the cutter mounting portion body 321 and the upper end P2 of the groove portion 3151 of the cover returns to its initial state and widens again.

[0051] Although preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements by those skilled in the art utilizing the basic concepts of the present invention as described in the following claims are also included within the scope of the present invention. [Industrial applicability]

[0052] This invention can be used in a device for removing the acetabular cup for artificial hip joints.

Claims

1. It includes a main shaft that can be attached to a power tool and rotated by the driving force of the power tool, and a cutter section provided at the front end of the main shaft, which can tilt along the acetabular portion into which the acetabular cup is implanted, and which cuts the acetabular portion while rotating by the main shaft, The cutter part is, A cutter tilt section that can tilt along the acetabular region around a virtual tilt axis. A cutter mounting portion is coupled to the cutter tilt portion so as to be slidable relative to the cutter tilt portion in a direction that moves towards or away from the virtual tilt axis, and A cutter that is detachably attached to the cutter mounting section. Includes, The cutter tilt section is, A first through hole that penetrates along the virtual tilt axis, A connecting bar with both ends fixed to the cutter mounting part, and A leaf spring fixed to both ends of the connecting bar, with a center between the two ends. Includes, The main shaft includes a cylinder portion that is inserted into the first through hole and has a second through hole formed in its longitudinal direction. The connecting bar is positioned within the second through-hole so as to be slidable in a direction toward or toward the virtual tilt axis within the second through-hole, The center of the leaf spring is supported by the inner wall of the second through hole. Acetabular cup removal device for artificial hip joints.

2. The second through hole has a circular cross-section, The acetabular cup removal device for an artificial hip joint according to claim 1, wherein the connecting bar has an arc shape in which a portion of its circumference has the same radius of curvature as the radius of curvature of the second through hole, and is capable of surface contact with the second through hole.

3. The acetabular cup removal device for an artificial hip joint according to claim 2, wherein the portion of the connecting bar other than the portion thereof does not come into contact with the second through hole.

4. The cutter mounting portion includes a cutter mounting portion main body having a third through hole into which the connecting bar is inserted. The acetabular cup removal device for an artificial hip joint according to claim 3, wherein the connecting bar does not rotate relative to the cutter mounting body within the third through hole, but tilts in conjunction with the tilt of the cutter mounting.

5. The other part of the connecting bar has three sides that are connected at right angles to each other. The acetabular cup removal device for an artificial hip joint according to claim 4, wherein the third through hole has a rectangular cross-section.

6. The acetabular cup removal device for an artificial hip joint according to claim 4, wherein the cutter tilt portion further includes a cover that covers the cutter mounting portion body and is fixed to the opposite surface of the cutter tilt portion.

7. A groove corresponding to the contour of the cutter mounting part body is formed on the inner surface of the cover. The acetabular cup removal device for an artificial hip joint according to claim 6, wherein a gap is formed between the upper end of the cutter mounting part and the upper end of the groove of the cover.

8. In the initial state when no external force is acting on the leaf spring, the portion of the connecting bar is in contact with the second through hole. The acetabular cup removal device for an artificial hip joint according to claim 2, wherein when an external force acts on the leaf spring, the leaf spring is compressed and the portion of the connecting bar is separated from the second through hole.

9. The acetabular cup removal device for an artificial hip joint according to claim 6, wherein the cover is fixed to the connecting bar by fasteners so as not to move relative to the opposing surface of the cutter tilt portion.

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