Acetabulum reinforcement implant and acetabulum reinforcement implant kit

Abstract

To provide an acetabulum reinforcement implant which can be easily attached to the pelvis.SOLUTION: An acetabulum reinforcement implant 1 according to one embodiment comprises: a dome part 2 which has a vertical frame and a lateral frame that are bent along the spherical surface corresponding to the acetabulum 92 and intersect with each other; a flat pallet part 3 which is bent upward from the vertical frame and is screwed to the ilium 91; and a hook part 4 which extends downward from the vertical frame and is engaged with an obturator foramen. The hook part 4 is inclined to the front side of the pelvis 9 with respect to the vertical frame and is twisted so as to approach the inner side of the pelvis 9 toward the front side of the pelvis 9 with respect to the vertical frame such that the pallet part 3 is orthogonal to the inside-outside direction of the pelvis 9 and a vertical axis 1A projecting a center line 21a of the vertical frame 21 onto a plane along the pallet part 3 becomes in parallel to the pelvis plane when the acetabulum reinforcement implant 1 is attached to the pelvis 9.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to an acetabular reinforcement implant and an acetabular reinforcement implant kit including the acetabular reinforcement implant. [Background technology]

[0002] Conventionally, when the hip joint is severely destroyed due to diseases such as osteoarthritis of the hip joint or femoral head necrosis, total hip arthroplasty (THA) is performed to replace the destroyed hip joint with an artificial hip joint. In this THA, a roughly hemispherical socket may be attached to the acetabulum, or an acetabular reinforcement implant may be attached to the pelvis to reinforce and reconstruct the acetabulum. In addition, an acetabular reinforcement implant may also be used for re-replacement when the socket attached to the acetabulum in THA collapses.

[0003] For example, Non-Patent Document 1 discloses an acetabular reinforcement implant 100 as shown in Fig. 8. This acetabular reinforcement implant 100 includes a dome portion 110, a pallet portion 120, and a hook portion .

[0004] The dome portion 110 includes a vertical frame 111 and a horizontal frame 112 that are curved along a spherical surface corresponding to the acetabulum and intersect with each other. The pallet portion 120 is bent upward from the vertical frame 111 of the dome portion 110. The pallet portion 120 is flat and is screwed to the ilium. The hook portion 130 extends downward from the vertical frame 111 of the dome portion 110. The hook portion 130 is engaged with the obturator foramen.

[0005] The acetabular reinforcement implant 100 has a shape symmetrical with respect to the center line of the vertical frame 111 of the dome portion 110 so that it can be used for both the left and right feet.

[0006] Non-Patent Document 2 discloses an acetabular reinforcement implant that differs from the acetabular reinforcement implant 100 shown in Fig. 8 only in that the horizontal frame 112 is asymmetrical with respect to the center line of the vertical frame 111. Specifically, in this acetabular reinforcement implant, the length of the portion of the horizontal frame 112 located on the left side of the vertical frame 111 (the front branch for the left foot, and the rear branch for the right foot) and the length of the portion located on the right side (the rear branch for the left foot, and the front branch for the right foot) when viewed from the inside of the dome part 110 are different for the left and right feet. That is, in both the acetabular reinforcement implant for the left foot and the acetabular reinforcement implant for the right foot, the front branch is set shorter than the rear branch. [Prior art documents] [Non-patent literature]

[0007] [Non-Patent Document 1] Emmanuel Gibon et al., "Acetabular reinforcement rings associated with allograft for severe acetabular defects," International Orthopaedics, September 13, 2018. [Non-Patent Document 2] Chiaki Tanaka and 3 others, "Acetabular reconstruction using a Kerboull-type acetabular reinforcement device and hydroxyapatite granules: a 3- to 8-year follow-up study," Journal of Arthroplasty, September 1, 2003. Summary of the Invention [Problem to be solved by the invention]

[0008] However, the acetabular augmentation implant 100 having a generally symmetrical shape as described above and the acetabular augmentation implant having a symmetrical shape except for the lateral frame 112 are often difficult to install because they are not designed to anatomically fit the pelvis. Moreover, skill and experience are required to attach the acetabular augmentation implant having a generally symmetrical shape or the symmetrical shape except for the lateral frame to the pelvis.

[0009] Therefore, an object of the present invention is to provide an acetabular reinforcement implant that can be easily attached to the pelvis. Another object of the present invention is to provide an acetabular reinforcement implant kit that includes the acetabular reinforcement implant. [Means for solving the problem]

[0010] The present invention provides an acetabular reinforcement implant to be attached to the pelvis, comprising: a dome portion including a vertical frame and a horizontal frame that are curved along a spherical surface corresponding to the acetabulum and intersect each other; a flat pallet portion that bends upward from the vertical frame and is screwed to the ilium; and a hook portion that extends downward from the vertical frame and engages with the obturator foramen, wherein when the acetabular reinforcement implant is attached to the pelvis, the pallet portion is perpendicular to the medial-lateral direction of the pelvis, and the hook portion is inclined toward the front of the pelvis relative to the vertical frame and twisted toward the front of the pelvis relative to the vertical frame so as to approach the inside of the pelvis toward the front of the pelvis, so that the vertical axis obtained by projecting the center line of the vertical frame onto a plane along the pallet portion is parallel to the anterior pelvic plane when the acetabular reinforcement implant is attached to the pelvis.

[0011] The present invention also provides an acetabular reinforcement implant kit comprising the above-mentioned acetabular reinforcement implant, a resin augment interposed between the pallet portion of the acetabular reinforcement implant and the ilium, and a hemispherical liner fixed to the dome portion of the acetabular reinforcement implant with cement. Effect of the Invention

[0012] According to the present invention, there is provided an acetabular reinforcement implant that can be easily attached to a pelvis, and an acetabular reinforcement implant kit that includes the acetabular reinforcement implant. [Brief description of the drawings]

[0013] [Figure 1] FIG. 1 is a perspective view of an acetabular augmentation implant according to one embodiment of the present invention. [Diagram 2] 1(a), (b) and (c) are top, front and bottom views, respectively, of the acetabular augmentation implant. [Diagram 3] 1(a), (b) and (c) are right side, rear and left side views, respectively, of the acetabular augmentation implant. [Figure 4] (a) and (b) are front and side views, respectively, of a pelvis with an acetabular augmentation implant installed. [Diagram 5] 13(a) and (b) are front and side views, respectively, of a pelvis for explaining an acetabular reinforcement implant kit. [Figure 6] FIG. [Figure 7] 1(a) to 1(c) are diagrams illustrating a method of using the acetabulum reinforcing implant kit. [Figure 8] FIG. 1 is a perspective view of a conventional acetabular augmentation implant. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] 1, 2(a) to (c), and 3(a) to (c) show an acetabular reinforcement implant 1 according to one embodiment of the present invention. As shown in Figs. 4(a) and (b), this acetabular reinforcement implant 1 is attached to a pelvis 9, and includes a dome portion 2, a pallet portion 3, and a hook portion 4. For example, the acetabular reinforcement implant 1 is made of a titanium alloy.

[0015] In this embodiment, the acetabular reinforcement implant 1 is for the left foot. That is, as shown in Fig. 2(b), in a front view seen from the inside of the dome portion 2, the left side is the front of the pelvis 9 and the right side is the rear of the pelvis 9. However, the acetabular reinforcement implant 1 may also be for the right foot.

[0016] The dome portion 2 includes a vertical frame 21 and a horizontal frame 22 that curve along a spherical surface 10 (see FIGS. 3(a) and (c)) that corresponds to the acetabulum 92 (see FIGS. 4(a) and (b)) and intersect with each other. The vertical frame 21 extends in the up-down direction at a constant width while curving along the spherical surface 10, and the horizontal frame 22 extends in the horizontal direction (i.e., the width direction of the vertical frame 21) at a constant width while curving along the spherical surface 10.

[0017] The horizontal frame 22 includes a front branch 23 located in front of the vertical frame 21 in the front-rear direction of the pelvis 9, and a rear branch 24 located behind the vertical frame 21. In this embodiment, the front branch 23 is shorter than the rear branch 24. For example, the length L1 of the front branch 23 in the width direction of the vertical frame 21 (see FIG. 2(b)) is 30% or more and less than 50% of the diameter of the spherical surface 10, and the length L2 of the rear branch 24 in the width direction of the vertical frame 21 (see FIG. 2(b)) is 40% or more and 50% or less of the diameter of the spherical surface 10.

[0018] In the conventional symmetrical acetabular reinforcement implant 100 shown in Fig. 8, the anterior branch may protrude from the acetabulum and adversely affect the iliopsoas tendon located in front. In contrast, if the anterior branch 23 is shorter than the posterior branch 24 as in this embodiment, the anterior branch 23 can be prevented from protruding from the acetabulum 92. In particular, if the lengths of the anterior branch 23 and the posterior branch 24 are set as described above, the anterior branch 23 can be prevented from protruding from the acetabulum 92 as much as possible. However, if the lengths of both the anterior branch 23 and the posterior branch 24 are short, the anterior branch 23 may be the same length as the posterior branch 24.

[0019] Furthermore, the dome portion 2 includes a small front branch 25 that extends laterally from the vertical frame 21 above the front branch 23 while curving along the spherical surface 10, and a small rear branch 26 that extends laterally from the vertical frame 21 above the rear branch 24 while curving along the spherical surface 10. These small front branches 25 and small rear branches 26 have approximately the same length.

[0020] The pallet portion 3 is bent upward from the vertical frame 21 of the dome portion 2. The pallet portion 3 is flat, and is screwed to the ilium 91 (see FIGS. 4(a) and (b)). The pallet portion 3 is provided with a plurality of screw insertion holes 31 through which screws that are screwed into the ilium 91 are inserted.

[0021] In this embodiment, the pallet unit 3 extends from the vertical frame 21 toward the front of the pelvis 9. In other words, the center of the pallet unit 3 is located forward of the pelvis 9 relative to the center line 21a of the vertical frame 21. More specifically, the pallet unit 3 has a generally boomerang-like shape that points upward, and one end of the pallet unit 3 is connected to the vertical frame 21.

[0022] However, the pallet portion 3 does not necessarily need to extend from the vertical frame 21 toward the front of the pelvis 9, and the center of the pallet portion 3 may be located on an extension of the center line 21a of the vertical frame 21.

[0023] In this embodiment, the screw insertion holes 31 include a first screw insertion hole 31A, a second screw insertion hole 31B, a third screw insertion hole 31C, and a fourth screw insertion hole 31D. However, the number of the screw insertion holes 31 may be two or three, or may be five or more.

[0024] The first screw insertion hole 31A is located above the vertical frame 21, the second screw insertion hole 31B is located in front of and above the first screw insertion hole 31A, the third screw insertion hole 31C is located in front of and below the second screw insertion hole 31B, and the fourth screw insertion hole 31D is located in front of and below the third screw insertion hole 31C. With this configuration, by inserting a screw into the third screw insertion hole 31C or the fourth screw insertion hole 31D, the acetabular reinforcement implant 1 can be firmly fixed by utilizing the thick host bed bone near the anterior inferior iliac spine.

[0025] Furthermore, the pallet part 3 is provided with at least one wire insertion hole 32 through which a wire for temporary fixing is inserted. In this embodiment, the number of wire insertion holes 32 is three. The diameter of each wire insertion hole 32 is smaller than the diameter of the screw insertion hole 31. One wire insertion hole 32 is located below the second screw insertion hole 31B and between the first screw insertion hole 31A and the third screw insertion hole 31C. The remaining two wire insertion holes 32 are aligned along the contour of the pallet part 3 above the third screw insertion hole 31C. With this configuration, the acetabular reinforcement implant 1 can be temporarily fixed by inserting a wire through the wire insertion hole 32. This makes it easy to fix the acetabular reinforcement implant 1.

[0026] The hook portion 4 extends downward from the vertical frame 21 of the dome portion 2. The hook portion 4 engages with a closed hole 93 (see Figs. 4(a) and (b)). The hook portion 4 is formed by folding back a plate portion continuous with the vertical frame 21 in the opposite direction to the vertical frame 21.

[0027] The hook portion 4 is inclined toward the front of the pelvis 9 with respect to the vertical frame 21 of the dome portion 2. In addition, the hook portion 4 is twisted with respect to the vertical frame 21 so as to approach the inside of the pelvis 9 toward the front of the pelvis 9.

[0028] More specifically, the inclination and twist of the hook portion 4 are set so that, when the acetabular reinforcement implant 1 is attached to the pelvis 9, the pallet portion 3 is perpendicular to the medial-lateral direction of the pelvis 9, and the vertical axis 1A obtained by projecting the center line 21a of the vertical frame 21 onto a plane along the pallet portion 3 is parallel to the anterior pelvic plane (APP), as shown in Figures 4(a) and (b). The APP is a plane that includes both anterior superior iliac spines and the pubic tubercle.

[0029] In other words, if the up-down direction along the APP is defined as the X-axis, the left-right direction of the pelvis 9 along the APP as the Y-axis, and the direction perpendicular to the APP as the Z-axis, the vertical axis 1A of the acetabular reinforcement implant 1 is parallel to the Y-axis, and the horizontal axis 1B of the acetabular reinforcement implant 1 (horizontal axis 1B is perpendicular to vertical axis 1A on a plane along the pallet portion 3) is parallel to the Z-axis.

[0030] For example, the inclination angle of the hook portion 4 with respect to the vertical frame 21, i.e., the angle θ1 between the center line 21a of the vertical frame 21 and the center line 4a of the hook portion 4 (see FIG. 2(b)), is 10 degrees or more and 30 degrees or less. For example, the twist angle of the hook portion 4 with respect to the vertical frame 21, i.e., the angle θ2 between the width direction of the vertical frame 21 and the width direction of the hook portion 4 (see FIG. 2(a)), is 5 degrees or more and 15 degrees or less.

[0031] In such an acetabular reinforcement implant 1, the acetabular reinforcement implant 1 has a shape that anatomically fits the pelvis 9, so that the acetabular reinforcement implant 1 can be easily attached to the pelvis 9. When the inclination of the acetabulum with respect to the APP was actually measured for 264 subjects, the subjects with an inclination angle of 20 to 30 degrees were about 36%, the subjects with an inclination angle of 15 to 25 degrees were about 50%, and the subjects with an inclination angle of 10 to 20 degrees were about 48%. Therefore, as described above, it is desirable that the inclination angle of the hook portion 4 with respect to the vertical frame 21 is 10 degrees or more and 30 degrees or less. In addition, when the torsion of the obturator foramen with respect to the APP was measured for the same 264 subjects, the obturator foramen was twisted inward toward the front in about 71% of the subjects, and the obturator foramen was twisted outward toward the front in about 29% of the subjects. In addition, the mean obturator torsion angle among subjects whose obturator foramen was twisted inward toward the front was 8.3 degrees, with a standard deviation of 5.9 degrees (i.e., the main distribution range was 8.3±5.9 degrees). Therefore, as described above, it is desirable that the hook portion 4 is twisted toward the front of the pelvis 9 relative to the vertical frame 21 and toward the inside of the pelvis 9, and that the torsion angle of the hook portion 4 relative to the vertical frame 21 is 5 degrees or more and 15 degrees or less.

[0032] Moreover, in the acetabular reinforcement implant 1 of this embodiment, the longitudinal axis 1A of the acetabular reinforcement implant 1 is parallel to the vertical direction along the APP, so that the acetabular reinforcement implant 1 itself can be used as a guide for the anatomical landmarks of the pelvis 9. That is, if the acetabular reinforcement implant 1 is installed so that the longitudinal axis 1A of the acetabular reinforcement implant 1 is parallel to the vertical direction along the APP, it becomes possible to install the hemispherical liner 8 (see FIG. 7(c)) fixed to the dome part 2 of the acetabular reinforcement implant 1 at the installation angle according to the preoperative plan. This allows ideal reconstruction of the hip joint, and a wide range of joint motion can be achieved. As a result, it is expected to have the effect of reducing the occurrence of complications such as dislocation and loosening of the acetabular reinforcement implant 1.

[0033] Furthermore, in this embodiment, since the pallet portion 3 extends from the vertical frame 21 toward the front of the pelvis 9, a wide support area for the pallet portion 3 by the ilium 91 can be ensured.

[0034] Here, a description will be given of a simulation performed to confirm the usefulness of the acetabular reinforcement implant 1 of this embodiment. In this simulation, it was verified how much deviation occurs from the target angle in the implant attachment angle (flexion / extension angle of the implant relative to the APP, adduction / abduction angle and ante / post rotation angle of the pallet part relative to the plane perpendicular to the APP) when the acetabular reinforcement implant 1 is used and when a conventional acetabular reinforcement implant 100 shown in Fig. 8 is used.

[0035] First, six pelvises with acetabular diameters of approximately 52 mm were randomly selected from the pelvic CT data of approximately 1,500 Japanese patients, and six life-size acetabular models were created from the CT data using a 3D printer. The acetabular reinforcement implant 1 of this embodiment (a resin augment 6 attached to a pallet portion 3, as described below) and a conventional acetabular reinforcement implant 100 were attached to these six acetabular models, and the implant attachment angle was measured.

[0036] The installation of the acetabular reinforcement implant 1,100 into the acetabular model was performed by five examiners with different experiences (an orthopedic surgeon with 28 years of experience, an orthopedic surgeon with 12 years of experience, an orthopedic surgeon with 7 years of experience, an orthopedic surgeon with 5 years of experience, and a medical student). Each examiner installed the acetabular reinforcement implant 1,100 into the acetabular model three times with an interval of at least one week, and the implant installation angle was measured each time.

[0037] The accuracy of the acetabular augmentation implant 1 of this embodiment was statistically significantly higher (Mann-Whitney U test) than that of the conventional acetabular augmentation implant 100 for all of the implant's adduction / abduction angles, anteversion / retroversion angles, and flexion / extension angles. The average absolute error values ​​for the target mounting angles of the acetabular augmentation implant 1 of this embodiment and the conventional acetabular augmentation implant 100 were 0.8±0.7 degrees and 3.1±1.7 degrees, respectively, for the adduction / abduction angles, 5.3±2.4 degrees and 11.1±4.0 degrees, respectively, for the anteversion / retroversion angles, and 1.5±1.1 degrees and 3.1±2.6 degrees, respectively, for the flexion / extension angles.

[0038] Furthermore, the mean square value of the examiner factor, which represents the inter-examiner error, was smaller for the acetabular reinforcement implant 1 of this embodiment than for the conventional acetabular reinforcement implant 100. The mean squares of the installation angles of the acetabular reinforcement implant 1 of this embodiment and the conventional acetabular reinforcement implant 100 were 0.82 and 3.17 for the adduction and abduction angles, 0.19 and 8.51 for the anteversion and retroversion angles, and 33.1 and 142.0 for the flexion and extension angles. In other words, it was found that the acetabular reinforcement implant 1 of this embodiment has less error in the installation angle regardless of the surgeon's level of experience and whoever installs it.

[0039] Next, an acetabular reinforcement implant kit 5 including the acetabular reinforcement implant 1 will be described with reference to FIGS. 5(a) and (b), FIG. 6, and FIGS. 7(a) to (c).

[0040] In addition to the acetabular reinforcement implant 1, the acetabular reinforcement implant kit 5 includes an augment 6 interposed between the pallet portion 3 of the acetabular reinforcement implant 1 and the ilium 91, a hemispherical liner 8 fixed to the dome portion 2 of the acetabular reinforcement implant 1 with cement, and an installation guide 7 for the liner 8.

[0041] The augment 6 is made of a resin such as polyethylene. As shown by the two-dot chain line in Fig. 6 and Fig. 5(a), the augment 6 is originally a columnar member extending with a certain cross-sectional shape similar to the pallet portion 3, and is cut to an appropriate thickness during surgery. The distance from the pallet portion 3 of the acetabular reinforcement implant 1 to the ilium 91 can be measured using a 3D template before surgery.

[0042] In this way, by adjusting the thickness of the augment 6 to match the gap between the pallet portion 3 of the acetabular reinforcement implant 1 and the ilium 91, the acetabular reinforcement implant 1 can be installed so that the vertical axis 1A of the acetabular reinforcement implant 1 is parallel to the up and down direction along the APP.

[0043] The cut augment 6 is attached to the pallet portion 3 of the acetabular reinforcement implant 1 from the back side. The augment 6 is provided with a plurality of openings 61 through which screws to be screwed into the ilium 91 are inserted at positions corresponding to the screw insertion holes 31 of the pallet portion 3. Each opening 61 may be a through hole or a notch.

[0044] The liner 8 is made of a resin such as polyethylene. A femoral head attached to a stem embedded in the femur is inserted into the liner 8. The liner 8 has a ring-shaped end surface that forms a circular opening.

[0045] The installation guide 7 is for determining the installation angle of the liner 8. The installation guide 7 can be attached to the pallet portion 3 of the acetabulum reinforcement implant 1 from the front side.

[0046] Specifically, the installation guide 7 includes a base 71 having a shape similar to that of the pallet portion 3, an arc portion 73 that follows the periphery of the end face of the liner 8, and an arm portion 72 that connects the base 71 and the arc portion 73. The arc portion 73 is curved along an installation reference plane, and an outward opening angle, which is the angle of the installation reference plane with respect to the X-axis of the APP, is, for example, 32 to 40 degrees, and a forward opening angle, which is the angle of the installation reference plane with respect to the Z-axis of the APP, is, for example, 4.7 to 25.4 degrees.

[0047] It is preferable to prepare a plurality of installation guides 7 with different lateral opening angles and anterior opening angles. With this configuration, an appropriate installation guide 7 can be used according to the hip joint angle of each patient.

[0048] When fixing the liner 8 to the dome portion 2 of the acetabular reinforcement implant 1, first, as shown in FIG. 7(a), the installation guide 7 is attached to the pallet portion 3 of the acetabular reinforcement implant 1. Next, cement is applied to the inner surface of the dome portion 2, and the liner 8 is inserted into the dome portion 2 as shown in FIG. 7(b). At this time, the periphery of the end face of the liner 8 is aligned with the arc portion 73 of the installation guide 7. This allows the liner 8 to be installed at the installation angle according to the preoperative plan, in other words, the preoperative plan can be accurately reproduced. After the cement has hardened, the installation guide 7 is removed as shown in FIG. 7(c).

[0049] (summary) In a first aspect, the present invention provides an acetabular reinforcement implant to be attached to a pelvis, comprising a dome portion including a vertical frame and a horizontal frame that curve along a spherical surface corresponding to the acetabulum and intersect each other, a flat pallet portion that bends upward from the vertical frame and is screwed to the ilium, and a hook portion that extends downward from the vertical frame and engages with the obturator foramen, wherein when the acetabular reinforcement implant is attached to the pelvis, the pallet portion is perpendicular to the medial-lateral direction of the pelvis, and the hook portion is inclined toward the front of the pelvis relative to the vertical frame and twisted toward the front of the pelvis relative to the vertical frame, approaching the inside of the pelvis toward the front of the pelvis, so that the vertical axis obtained by projecting the center line of the vertical frame onto a plane along the pallet portion is parallel to the anterior pelvic plane when the acetabular reinforcement implant is attached to the pelvis.

[0050] According to the above configuration, since the acetabular reinforcement implant has a shape that anatomically fits the pelvis, the acetabular reinforcement implant can be easily attached to the pelvis. Moreover, since the longitudinal axis of the acetabular reinforcement implant is parallel to the vertical direction along the APP, the acetabular reinforcement implant itself can be used as a guide for the anatomical indicators of the pelvis. That is, if the acetabular reinforcement implant is installed so that the longitudinal axis of the acetabular reinforcement implant is parallel to the vertical direction along the APP, it becomes possible to install the hemispherical liner fixed to the dome part of the acetabular reinforcement implant at the installation angle according to the preoperative plan. Therefore, ideal reconstruction of the hip joint is possible, and a wide range of joint motion can be achieved. As a result, it is expected to have an effect of reducing the occurrence of complications such as dislocation and loosening of the acetabular reinforcement implant.

[0051] As a second aspect, in the first aspect, the pallet portion may extend from the vertical frame toward the front of the pelvis. With this configuration, a wide support area of ​​the pallet portion by the ilium can be ensured.

[0052] As a third aspect, in the second aspect, the pallet portion may be provided with a plurality of screw insertion holes, and the plurality of screw insertion holes may include a first screw insertion hole located above the vertical frame, a second screw insertion hole located in front of and above the first screw insertion hole, a third screw insertion hole located in front of and below the second screw insertion hole, and a fourth screw insertion hole located in front of and below the third screw insertion hole. According to this configuration, by inserting a screw into the third screw insertion hole or the fourth screw insertion hole, the acetabular reinforcement implant can be firmly fixed by utilizing the thick host bed bone near the anterior inferior iliac spine.

[0053] As a fourth aspect, in any one of the first to third aspects, the pallet portion may be provided with a plurality of screw insertion holes and at least one wire insertion hole having a smaller diameter than the plurality of screw insertion holes. With this configuration, the acetabular reinforcement implant can be temporarily fixed by inserting a wire into the wire insertion hole. This makes it easy to fix the acetabular reinforcement implant.

[0054] As a fifth aspect, in any of the first to fourth aspects, for example, the inclination angle of the hook portion relative to the vertical frame may be greater than or equal to 10 degrees and less than or equal to 30 degrees, and the twist angle of the hook portion relative to the vertical frame may be greater than or equal to 5 degrees and less than or equal to 15 degrees.

[0055] As a sixth aspect, in any of the first to fifth aspects, the horizontal frame may have an anterior branch located in front of the vertical frame and a posterior branch located behind the vertical frame in the anterior-posterior direction of the pelvis, and the anterior branch may be shorter than the posterior branch. In a conventional acetabular reinforcement implant having a symmetrical shape, the anterior branch may protrude from the acetabulum. In contrast, if the anterior branch is shorter than the posterior branch, the anterior branch may be prevented from protruding from the acetabulum.

[0056] As a seventh aspect, in the sixth aspect, the length of the anterior branch in the width direction of the vertical frame may be 30% or more and less than 50% of the diameter of the sphere, and the length of the posterior branch in the width direction of the vertical frame may be 40% or more and 50% or less of the diameter of the sphere. With this configuration, it is possible to prevent the anterior branch from protruding from the acetabulum as much as possible.

[0057] In an eighth aspect, the present invention provides an acetabular reinforcement implant kit comprising an acetabular reinforcement implant according to any one of the first to seventh aspects, a resin augment interposed between the pallet portion of the acetabular reinforcement implant and the ilium, and a hemispherical liner fixed to the dome portion of the acetabular reinforcement implant with cement. According to this configuration, by adjusting the thickness of the augment according to the gap between the pallet portion of the acetabular reinforcement implant and the ilium, the acetabular reinforcement implant can be installed so that the longitudinal axis of the acetabular reinforcement implant is parallel to the up-down direction along the APP.

[0058] As a ninth aspect, the acetabular reinforcement implant kit according to the eighth aspect may further include an installation guide that can be attached to the pallet portion of the acetabular reinforcement implant and that determines the installation angle of the liner. With this configuration, the liner can be installed at the installation angle according to the preoperative plan, in other words, the preoperative plan can be accurately reproduced. [Explanation of symbols]

[0059] 1 Acetabular augmentation implant 10 spherical 2 Dome section 21 Vertical Frame 22 Horizontal Frame 23 Front Branch 24 Posterior branch 3 Pallet section 31, 31A~31D Screw insertion holes 32 Wire insertion hole 4 Hook part 5 Acetabular augmentation implant kit 6 Augmented 7 Installation Guide 8 Liner 9 Pelvis 91 Ilium 92 Acetabulum 93 Obturator foramen

Claims

1. 1. An acetabular augmentation implant for attachment to a pelvis, comprising: A dome portion including a vertical frame and a horizontal frame that are curved along a spherical surface corresponding to the acetabulum and intersect with each other; A flat pallet portion that bends upward from the vertical frame and is screwed to the ilium; A hook portion extending downward from the vertical frame and adapted to engage with an obturator foramen; An acetabular reinforcement implant in which, when the acetabular reinforcement implant is attached to the pelvis, the pallet portion is perpendicular to the medial-lateral direction of the pelvis, and the vertical axis of the center line of the vertical frame projected onto a plane along the pallet portion is parallel to the anterior pelvic plane, so that the hook portion is inclined toward the front of the pelvis relative to the vertical frame and twisted toward the front of the pelvis and toward the inside of the pelvis relative to the vertical frame.

2. The acetabular reinforcement implant according to claim 1 , wherein the pallet portion extends from the vertical frame toward the front of the pelvis.

3. The pallet portion is provided with a plurality of screw insertion holes, The acetabular reinforcement implant of claim 2, wherein the plurality of screw insertion holes include a first screw insertion hole located above the vertical frame, a second screw insertion hole located in front of and above the first screw insertion hole, a third screw insertion hole located in front of and below the second screw insertion hole, and a fourth screw insertion hole located in front of and below the third screw insertion hole.

4. An acetabular reinforcement implant as described in any one of claims 1 to 3, wherein the pallet portion has a plurality of screw insertion holes and at least one wire insertion hole having a smaller diameter than the plurality of screw insertion holes.

5. The inclination angle of the hook portion with respect to the vertical frame is 10 degrees or more and 30 degrees or less, The acetabulum reinforcement implant according to any one of claims 1 to 3, wherein the torsional angle of the hook portion relative to the vertical frame is greater than or equal to 5 degrees and less than or equal to 15 degrees.

6. The horizontal frame has a front branch located in front of the vertical frame and a rear branch located behind the vertical frame in the front-rear direction of the pelvis, The acetabular reinforcement implant according to any one of claims 1 to 3, wherein the anterior branch is shorter than the posterior branch.

7. The length of the front branch in the width direction of the vertical frame is 30% or more and less than 50% of the diameter of the spherical surface, The acetabular reinforcement implant according to claim 6 , wherein the length of the posterior branch in the width direction of the vertical frame is between 40% and 50% of the diameter of the spherical surface.

8. An acetabular reinforcement implant according to any one of claims 1 to 3; A resin augment is interposed between the pallet portion of the acetabular reinforcement implant and the ilium; a hemispherical liner cemented to the dome portion of the acetabular augmentation implant; An acetabular reinforcement implant kit comprising:

9. The acetabular reinforcement implant kit of claim 8 , further comprising an installation guide for determining an installation angle of the liner, the installation guide being attachable to the pallet portion of the acetabular reinforcement implant.

Images