Acetabular bone reinforcement implants and acetabular bone reinforcement implant kits

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 Art

[0002] Conventionally, when the hip joint is severely damaged due to diseases such as osteoarthritis or femoral head necrosis, total hip arthroplasty (THA) is performed to replace the damaged hip joint with an artificial hip joint. In this THA, a substantially hemispherical socket may be attached to the acetabulum, or an acetabular reinforcement implant for reinforcing and reconstructing the acetabulum may be attached to the pelvis. Note that the acetabular reinforcement implant may also be used for replacement when the socket attached to the acetabulum in THA fails.

[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 130.

[0004] The dome portion 110 curves along a spherical surface corresponding to the acetabulum and includes vertical frames 111 and horizontal frames 112 that intersect 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 a closed hole.

[0005] The acetabular reinforcement implant 100 has a shape symmetric 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 foot and the right foot.

[0006] Furthermore, Non-Patent Document 2 discloses an acetabular reinforcement implant that differs from the acetabular reinforcement implant 100 shown in Figure 8 only in that the transverse frame 112 is asymmetrical with respect to the center line of the longitudinal frame 111. Specifically, in this acetabular reinforcement implant, when viewed from the inside of the dome portion 110, the length of the portion of the transverse frame 112 located on the left side of the longitudinal frame 111 (anterior ramus for the left foot, posterior ramus for the right foot) and the length of the portion located on the right side (posterior ramus for the left foot, anterior ramus for the right foot) are different for the left foot and the right foot. In other words, in both the left foot and right foot acetabular reinforcement implants, the anterior ramus is set to be shorter than the posterior ramus. [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, et al., "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. [Overview of the project] [Problems that the invention aims to solve]

[0008] However, apart from the symmetrical acetabular reinforcement implants 100 and lateral frame 112 described above, symmetrical acetabular reinforcement implants are often difficult to install because they are not anatomically designed to fit the pelvis. Moreover, attaching acetabular reinforcement implants that are symmetrical overall or excluding the lateral frame to the pelvis requires skill and experience.

[0009] Therefore, the present invention aims to provide an acetabular reinforcement implant that can be easily attached to the pelvis. The present invention also aims 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 for attachment to the pelvis, comprising: a dome portion including longitudinal and transverse frames that curve along a spherical surface corresponding to the acetabulum and intersect each other; a flat pallet portion that bends upward from the longitudinal frame and is screwed to the ilium; and a hook portion that extends downward from the longitudinal frame and engages with an obturator orifice, wherein when the acetabular reinforcement implant is attached to the pelvis, the pallet portion is perpendicular to the inward and outward directions of the pelvis, and the longitudinal axis obtained by projecting the center line of the longitudinal frame onto a plane along the pallet portion is parallel to the anterior pelvic plane, such that the hook portion is inclined toward the front of the pelvis with respect to the longitudinal frame and is twisted toward the front of the pelvis toward the inward direction of the pelvis with respect to the longitudinal frame.

[0011] Furthermore, the present invention 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 with cement to the dome portion of the acetabular reinforcement implant. [Effects of the Invention]

[0012] The present invention provides an acetabular reinforcement implant that can be easily attached to the pelvis, and an acetabular reinforcement implant kit including the acetabular reinforcement implant. [Brief explanation of the drawing]

[0013] [Figure 1] This is a perspective view of an acetabular reinforcement implant according to one embodiment of the present invention. [Figure 2] (a), (b), and (c) are the top, front, and bottom views, respectively, of the acetabular reinforcement implant. [Figure 3] (a), (b), and (c) are the right side view, posterior view, and left side view of the acetabular reinforcement implant, respectively. [Figure 4] (a) and (b) are frontal and lateral views, respectively, of a pelvis fitted with an acetabular reinforcement implant. [Figure 5] (a) and (b) are frontal and lateral views of the pelvis, respectively, illustrating an acetabular reinforcement implant kit. [Figure 6] This is a perspective view of augmentation. [Figure 7] (a) to (c) are diagrams illustrating how to use the acetabular reinforcement implant kit. [Figure 8] This is a perspective view of a conventional acetabular reinforcement implant. [Modes for carrying out the invention]

[0014] Figures 1, 2(a)-(c), and 3(a)-(c) show an acetabular reinforcement implant 1 according to one embodiment of the present invention. As shown in Figures 4(a) and (b), this acetabular reinforcement implant 1 is attached to the 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 the 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 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)) corresponding to the acetabulum 92 (see Figs. 4(a) and (b)) and intersect each other. The vertical frame 21 extends in the vertical direction with a constant width while curving along the spherical surface 10, and the horizontal frame 22 extends in the horizontal direction (that is, the width direction of the vertical frame 21) with 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 and a rear branch 24 located behind the vertical frame 21 in the front-rear direction of the pelvis 9. In this embodiment, the front branch 23 is shorter than the rear branch 24. For example, the length L1 (see Fig. 2(b)) of the front branch 23 in the width direction of the vertical frame 21 is 30% or more and less than 50% of the diameter of the spherical surface 10, and the length L2 (see Fig. 2(b)) of the rear branch 24 in the width direction of the vertical frame 21 is 40% or more and 50% or less of the diameter of the spherical surface 10.

[0018] In the conventional symmetrically shaped acetabular reinforcement implant 100 shown in Fig. 8, there was a risk that the front branch would protrude from the acetabulum and adversely affect the iliopsoas tendon existing in the front. In contrast, if the front branch 23 is shorter than the rear branch 24 as in this embodiment, it is possible to suppress the front branch 23 from protruding from the acetabulum 92. In particular, if the lengths of the front branch 23 and the rear branch 24 are set as described above, it is possible to prevent the front branch 23 from protruding from the acetabulum 92 as much as possible. However, when the lengths of both the front branch 23 and the rear branch 24 are short, the front branch 23 may have the same length as the rear branch 24.

[0019] Furthermore, the dome portion 2 includes a small front branch 25 that extends horizontally while curving along the spherical surface 10 from the vertical frame 21 above the front branch 23, and a small rear branch 26 that extends horizontally while curving along the spherical surface 10 from the vertical frame 21 above the rear branch 24. These small front branch 25 and small rear branch 26 have lengths of approximately the same degree as each other.

[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 screwed into the ilium 91 are inserted.

[0021] In the present embodiment, the pallet portion 3 extends from the vertical frame 21 toward the front of the pelvis 9. In other words, the center of the pallet portion 3 is located in front of the pelvis 9 with respect to the center line 21a of the vertical frame 21. More specifically, the pallet portion 3 has a substantially boomerang shape that tapers upward, and one end thereof is connected to the vertical frame 21.

[0022] However, the pallet portion 3 does not necessarily have 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 the extension line of the center line 21a of the vertical frame 21.

[0023] In the present 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 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 anterior to and above the first screw insertion hole 31A, the third screw insertion hole 31C is located anterior to and below the second screw insertion hole 31B, and the fourth screw insertion hole 31D is located anterior to and below the third screw insertion hole 31C. With this configuration, the acetabular reinforcement implant 1 can be firmly fixed using the thick bed bone near the anterior inferior iliac spine by inserting a screw through the third screw insertion hole 31C or the fourth screw insertion hole 31D.

[0025] Furthermore, the pallet portion 3 is provided with at least one wire insertion hole 32 through which a temporary fixing wire is inserted. In this embodiment, there are three wire insertion holes 32. 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 portion 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 holes 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 the closing hole 93 (see Figures 4(a) and (b)). The hook portion 4 is formed by folding back a plate-like portion that is 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 relative to the vertical frame 21 of the dome portion 2. Furthermore, the hook portion 4 is twisted toward the front of the pelvis 9 relative to the vertical frame 21 so as to move toward the inside of the pelvis 9.

[0028] More specifically, the inclination and twist of the hook portion 4 are set such that, as shown in Figures 4(a) and (b), 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 the plane along the pallet portion 3, is parallel to the anterior pelvic plane (APP). The APP is a plane that includes both anterior superior iliac spines and the pubic tubercle.

[0029] In other words, 、A The left-right direction of the pelvis 9 along the PP X shaft, The vertical direction along the APP is the Y-axis, When the direction perpendicular to the APP is defined 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 (the horizontal axis 1B is perpendicular to the vertical axis 1A on the plane along the pallet portion 3) is parallel to the Z-axis.

[0030] For example, the inclination angle of the hook portion 4 relative 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 Figure 2(b)), is between 10 degrees and 30 degrees. For example, the twist angle of the hook portion 4 relative 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 Figure 2(a)), is between 5 degrees and 15 degrees.

[0031] In this type of acetabular reinforcement implant 1, the implant has a shape that anatomically fits the pelvis 9, allowing for easy attachment to the pelvis 9. When the inclination of the acetabulum relative to the APP was measured in 264 subjects, approximately 36% had an inclination angle of 20-30 degrees, approximately 50% had an inclination angle of 15-25 degrees, and approximately 48% had an inclination angle of 10-20 degrees. Therefore, as mentioned above, it is desirable that the inclination angle of the hook portion 4 relative to the vertical frame 21 be between 10 and 30 degrees. Furthermore, when the torsion of the obturator foramen relative to the APP was measured in the same 264 subjects, approximately 71% of subjects had an obturator foramen twisted inward toward the front, and approximately 29% of subjects had an obturator foramen twisted outward toward the front. Furthermore, among subjects whose obturator foramen was twisted inward toward the front, the mean twist angle of the obturator foramen was 8.3 degrees, and the standard deviation was 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 toward the inward side of the pelvis 9 relative to the vertical frame 21, and that the twist angle of the hook portion 4 toward the vertical frame 21 is between 5 degrees and 15 degrees.

[0032] Furthermore, in the acetabular reinforcement implant 1 of this embodiment, the vertical axis 1A of the acetabular reinforcement implant 1 is parallel to the vertical direction along the APP, so the acetabular reinforcement implant 1 itself can be used as a guide for anatomical landmarks of the pelvis 9. In other words, by installing the acetabular reinforcement implant 1 so that the vertical 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 Figure 7(c)), which is fixed to the dome portion 2 of the acetabular reinforcement implant 1, at the installation angle planned preoperatively. As a result, ideal reconstruction of the hip joint becomes possible, and a wide range of joint motion can be achieved. Consequently, it is expected that the occurrence of complications such as dislocation and loosening of the acetabular reinforcement implant 1 will be reduced.

[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 secured.

[0034] Here, we will describe the simulation performed to confirm the usefulness of the acetabular reinforcement implant 1 of this embodiment. In this simulation, we verified how much deviation occurs from the target angle in the implant mounting angle (flexion and extension angles of the implant relative to the APP, adduction and abduction angles of the pallet portion relative to a plane perpendicular to the APP, and anteversion and retroversion angles) when the acetabular reinforcement implant 1 is attached to the pelvis, when the conventional acetabular reinforcement implant 100 shown in Figure 8 is used.

[0035] First, from pelvic CT data of approximately 1500 Japanese patients, six pelvises with an acetabular diameter of around 52 mm were randomly selected, and six life-size acetabular models were created using a 3D printer from the CT data of these six acetabular models. The acetabular reinforcement implant 1 of this embodiment (with the resin augmentation 6 described later attached to the pallet part 3) and the conventional acetabular reinforcement implant 100 were attached to these six acetabular models, and the implant attachment angle was measured.

[0036] The attachment of the acetabular reinforcement implant 1,100 to the acetabular model was performed by five examiners with varying levels of experience (a 28-year orthopedic surgeon, a 12-year orthopedic surgeon, a 7-year orthopedic surgeon, a 5-year orthopedic surgeon, and a medical student). Each examiner attached the acetabular reinforcement implant 1,100 to the acetabular model three times, with intervals of at least one week between each attachment, and the implant attachment angle was measured each time.

[0037] The acetabular reinforcement implant 1 of this embodiment showed statistically significantly higher accuracy than the conventional acetabular reinforcement implant 100 in terms of adduction / abduction angles, anteversion / reversion angles, and flexion / extension angles (Mann-Whitney U test). The mean absolute errors with respect to the target mounting angle for the acetabular reinforcement implant 1 of this embodiment and the conventional acetabular reinforcement implant 100 were 0.8±0.7 degrees and 3.1±1.7 degrees for adduction / abduction angles, 5.3±2.4 degrees and 11.1±4.0 degrees for anteversion / reversion angles, and 1.5±1.1 degrees and 3.1±2.6 degrees for flexion / extension angles.

[0038] Furthermore, the acetabular reinforcement implant 1 of this embodiment had a smaller mean square value for the examiner factor, which represents inter-examiner error, than the conventional acetabular reinforcement implant 100. The mean square values ​​of the mounting angles for the acetabular reinforcement implant 1 of this embodiment and the conventional acetabular reinforcement implant 100 were 0.82 and 3.17 for adduction and abduction angles, 0.19 and 8.51 for anteversion and retroversion angles, and 33.1 and 142.0 for flexion and extension angles. In other words, it was found that with the acetabular reinforcement implant 1 of this embodiment, the error in the mounting angle is small regardless of the operator's experience level, and regardless of who installs it.

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

[0040] The acetabular reinforcement implant kit 5 includes, in addition to the acetabular reinforcement implant 1, an augmentation 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] Augment 6 is made of a resin such as polyethylene. Augment 6 is originally a columnar member extending with a certain cross-sectional shape similar to the pallet portion 3, as shown by the dashed line in Figures 6 and 5(a), and is cut to the 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 its vertical axis 1A is parallel to the vertical direction along the APP.

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

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

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

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

[0047] It is preferable to prepare multiple installation guides 7 with different outward and forward opening angles. With this configuration, the appropriate installation guide 7 can be used according to the hip joint angle of each individual patient.

[0048] When fixing the liner 8 to the dome portion 2 of the acetabular reinforcement implant 1, first, as shown in Figure 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 Figure 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 as planned in 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 Figure 7(c).

[0049] (summary) In a first aspect, the present invention provides an acetabular reinforcement implant for attachment to the pelvis, comprising: a dome portion including longitudinal and transverse frames that curve along a spherical surface corresponding to the acetabulum and intersect each other; a flat pallet portion that bends upward from the longitudinal frame and is screwed to the ilium; and a hook portion that extends downward from the longitudinal frame and engages with an obturator hole, wherein when the acetabular reinforcement implant is attached to the pelvis, the pallet portion is perpendicular to the inward and outward directions of the pelvis, and the longitudinal axis obtained by projecting the center line of the longitudinal frame onto a plane along the pallet portion is parallel to the anterior pelvic plane, such that the hook portion is inclined toward the front of the pelvis with respect to the longitudinal frame and is twisted toward the front of the pelvis toward the inward direction of the pelvis with respect to the longitudinal frame.

[0050] According to the above configuration, the acetabular reinforcement implant has a shape that anatomically fits the pelvis, allowing for easy attachment to the pelvis. Furthermore, since the vertical 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 anatomical landmarks of the pelvis. In other words, by positioning the acetabular reinforcement implant so that its vertical axis is parallel to the vertical direction along the APP, it becomes possible to position the hemispherical liner fixed to the dome portion of the acetabular reinforcement implant at the pre-operatively planned positioning angle. This enables ideal hip joint reconstruction and allows for a wide range of motion. As a result, it is expected to reduce the occurrence of complications such as dislocation and loosening of the acetabular reinforcement implant.

[0051] In a second embodiment, in the first embodiment, the pallet portion may extend from the vertical frame toward the front of the pelvis. This configuration allows for a wider support area for the pallet portion by the ilium.

[0052] In a third embodiment, in the second embodiment, the pallet portion is provided with a plurality of screw insertion holes, 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. With this configuration, by inserting a screw into the third or fourth screw insertion hole, the acetabular reinforcement implant can be firmly fixed using the thick bed bone near the anterior inferior iliac spine.

[0053] In a fourth embodiment, in any of the first to third embodiments, 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 through the wire insertion hole. This makes it easy to fix the acetabular reinforcement implant.

[0054] In a fifth embodiment, in any of the first to fourth embodiments, for example, the inclination angle of the hook portion with respect to the vertical frame may be 10 degrees or more and 30 degrees or less, and the twist angle of the hook portion with respect to the vertical frame may be 5 degrees or more and 15 degrees or less.

[0055] In a sixth aspect, in any of the first to fifth aspects, the transverse frame has an anterior ramus located in front of the longitudinal frame and a posterior ramus located behind the longitudinal frame in the anterior-posterior direction of the pelvis, and the anterior ramus may be shorter than the posterior ramus. In conventional symmetrical acetabular reinforcement implants, the anterior ramus sometimes protrudes from the acetabulum. In contrast, if the anterior ramus is shorter than the posterior ramus, it is possible to suppress the protrusion of the anterior ramus from the acetabulum.

[0056] In a seventh embodiment, in the sixth embodiment, the length of the anterior ramus 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 ramus in the width direction of the vertical frame may be 40% or more and 50% or less of the diameter of the sphere. This configuration makes it possible to prevent the anterior ramus 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 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. With this configuration, by adjusting the thickness of the augment to match the gap between the pallet portion of the acetabular reinforcement implant and the ilium, the acetabular reinforcement implant can be installed so that its vertical axis is parallel to the vertical direction along the APP.

[0058] In a ninth aspect, in the eighth aspect, the acetabular reinforcement implant kit may further include an installation guide for determining the installation angle of the liner, which can be attached to the pallet portion of the acetabular reinforcement implant. This configuration allows the liner to be installed at the installation angle specified in the preoperative plan, in other words, the preoperative plan can be accurately reproduced. [Explanation of Symbols]

[0059] 1. Acetabular bone reinforcement implant 10 spherical 2 Dome section 21 Vertical Frames 22 horizontal frames 23 Front Branch 24 Posterior branch 3. Pallet section 31, 31A~31D Screw insertion holes 32 wire insertion holes 4. Hook section 5. Acetabular bone reinforcement implant kit 6 Augment 7. Installation Guide 8 Liners 9 Pelvis 91 Ilium 92 Acetabular bone 93 Obturator foramen

Claims

1. An acetabular reinforcement implant that is attached to the pelvis, A dome section including vertical and horizontal frames that curve along the spherical surface corresponding to the acetabulum and intersect with each other, A flat pallet section that bends upward from the aforementioned vertical frame and is screwed to the ilium, It comprises a hook portion that extends downward from the vertical frame and engages with a closing hole, An acetabular reinforcement implant in which, when the acetabular reinforcement implant is attached to the pelvis, the pallet portion is perpendicular to the inward and outward direction of the pelvis, and 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, such that the hook portion is inclined toward the front of the pelvis with respect to the vertical frame and is twisted toward the inward direction of the pelvis with respect 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 aforementioned pallet section is provided with multiple screw insertion holes. The acetabular reinforcement implant according to 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. The acetabular reinforcement implant according to any one of claims 1 to 3, wherein the pallet portion is 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.

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 acetabular reinforcement implant according to any one of claims 1 to 3, wherein the twist angle of the hook portion with respect to the vertical frame is 5 degrees or more and 15 degrees or less.

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

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 sphere. The acetabular reinforcement implant according to claim 6, wherein the length of the posterior branch in the width direction of the longitudinal frame is 40% or more and 50% or less of the diameter of the spherical surface.

8. An acetabular reinforcement implant according to any one of claims 1 to 3, A resin augment interposed between the pallet portion and the ilium of the acetabular reinforcement implant, A hemispherical liner fixed with cement to the dome portion of the aforementioned acetabular reinforcement implant, A acetabular reinforcement implant kit equipped with the necessary components.

9. The acetabular reinforcement implant kit according to claim 8, further comprising an installation guide for determining the installation angle of the liner, which can be attached to the pallet portion of the acetabular reinforcement implant.

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