AU2013326335A1

AU2013326335A1 - Cup for a cotyloid implant intended to be implanted in an acetabular cavity

Info

Publication number: AU2013326335A1
Application number: AU2013326335A
Authority: AU
Inventors: Christophe CHEVILLOTTE; Stephane Denjean; Thierry Gaillard; Olivier Guyen
Original assignee: HORIZON II
Current assignee: HORIZON II
Priority date: 2012-10-03
Filing date: 2013-10-01
Publication date: 2015-04-09
Also published as: EP2903565A1; FR2996118B1; BR112015007482A2; FR2996118A1; MX352354B; MX2015004164A; WO2014053768A1

Abstract

This cup (1) has an internal cavity (2), in order to accommodate an insert, and an outer surface (4) to be joined to the acetabulum. The outer surface (4) is a hemisphere which has an equatorial lip (10), a protruding equatorial region (20), and a polar region (30). The equatorial region (20) has a height (H20) parallel to the central axis (X4), and it has circular grooves (21, 22, 23), and oblique grooves which are arranged transversely with respect to the circular grooves (21, 22, 23) and which comprise primary oblique grooves (25.1) oriented to the right and secondary oblique grooves (25.2) oriented to the left.

Description

- 1 CUP FOR A COTYLOID IMPLANT INTENDED TO BE IMPLANTED IN AN ACETABULAR CAVITY The present invention relates to a cup for cotyloid implant intended to 5 be implanted in an acetabular cavity. The present invention applies to the field of orthopedic surgery of the hip, for replacing a hip cotyle. W09423670A1 or FR2653326A1 describes a cup for a hip prosthesis, which has an inner cavity, to house a cotyloid implant, and a substantially 10 hemispherical outer surface. An equatorial region of the outer surface has circular grooves which are coaxial with the central axis of the outer hemispherical surface. However, such a cup does not allow a sufficiently firm anchoring in the acetabulum, even after the bone reconstruction. Such a cup hence generally 15 requires anchoring screws, which risk causing the premature wear of the cotyloid insert. The present invention aims in particular at solving, entirely or partly, the aforementioned issues. To this aim, the object of the invention is a cup, for cotyloid implant 20 intended to be implanted in an acetabular cavity, the cup having: - an inner cavity suitable for housing a cotyloid insert; - an outer surface intended to be secured to the acetabulum, the outer surface generally having the shape of a half-spheroid centered on a central axis, the outer surface having an equatorial lip, an equatorial region 25 and a polar region, the equatorial region extending radially protruding with respect to the polar region and with respect to the equatorial lip, the equatorial region having a constant height measured in parallel with the central axis, the equatorial region having: o at least three circular grooves which are generally parallel and 30 which are generally coaxial with the central axis; the cup being characterized in that the equatorial region further has: o oblique grooves arranged transversally to the circular grooves and over all or part of the periphery of the equatorial region, the oblique grooves comprising: 35 - primary oblique grooves which are oriented on the right and which are positioned on a first peripheral portion of the equatorial region; and 6318872 1 (GHMatters) P99549.AU LYNT -2 - secondary oblique grooves which are oriented on the left and which are positioned on a second peripheral portion of the equatorial region, the second peripheral portion being distinct from the first peripheral portion. In the present application, the term "polar region" indicates a portion of a half 5 spheroid of which the transversal dimensions (diameter), measured perpendicularly to the central axis, are smaller than the transversal dimensions of the "equatorial region". In the present application, the term "half-spheroid" indicates a shape which approximately resembles a half-sphere. However, a half-sphere may cover a solid 10 angle larger than a half-sphere and it may have an imperfect spherical curvature, particularly with a polar region of slightly flattened curvature or larger than that of the equatorial region. Thus, such a cup may be anchored in the acetabulum in a firm manner, thanks to the circular grooves and the oblique grooves, and in a uniform manner 15 around the central axis, as the equatorial region has a constant height. Moreover, such a cup allows efficiently retaining the cotyloid insert, thanks to the equatorial lip. According to an embodiment of the invention, the equatorial region has four or five circular grooves. Thus, such a number of circular grooves ensure a particularly firm anchoring 20 of the cup in the acetabulum. According to an embodiment of the invention, each circular groove has a depth, measured perpendicularly to the central axis, ranging between 0.5 mm and 1.2 mm, preferably between 0.7 mm and 1.0 mm, and a width, measured in parallel with the central axis, ranging between 0.6 mm and 1.0 mm. 25 Thus, such a circular groove depth contributes to a firm anchoring of the cup in the acetabulum. The bottom of each circular groove has a spherical shape defined by milling. According to a variant of the invention, the equatorial lip is separated from the nearest circular groove by a distance, measured in parallel with the central axis, 30 between 2 mm and 3.2 mm. Thus, this distance forms a protruding ring which allows the cup to be press-fitted into the acetabulum. According to an embodiment, the equatorial lip has a constant height, measured in parallel with the central axis, and ranging between 0.5 mm and 2.5 mm, preferably between 1.2 mm and 1.8 mm. 35 Thus, such an equatorial lip, of constant height, ensures a uniform hold of the cotyloid insert in the cup. 6318872 1 (GHMatters) P99549.AU LYNT -3 According to an embodiment of the invention, the height of the equatorial region ranges between 6 mm and 15 mm, preferably ranging between 8 mm and 13 mm. Thus, such a height ensures the anchoring of the cup, despite a 5 limited machining area of the outer surface of the cup. According to an embodiment of the invention, each primary oblique groove forms with the central axis, in projection in the meridian plane of the half-spheroid which is the farthest from said primary oblique groove, a primary angle ranging between 8 degrees and 60 degrees, preferably 10 ranging between 10 degrees and 30 degrees; and In which each secondary oblique groove forms with the central axis, in projection in the meridian plane of the half-spheroid which is the farthest from said secondary oblique groove, a secondary angle ranging between 8 degrees and 60 degrees, preferably ranging between 10 degrees and 30 15 degrees. Thus, such primary and secondary angles allow a firm anchoring of the cup in the acetabulum. According to an embodiment of the invention, the primary oblique grooves are oriented according to a same primary angle, and in which the 20 secondary oblique grooves are oriented according to a same secondary angle. In other words, the primary oblique grooves are substantially parallel two by two, and the secondary oblique grooves are substantially parallel two by two. 25 Thus, it is relatively rapid to machine the primary and secondary oblique grooves. According to an embodiment of the invention, the first peripheral portion extends over one half of the equatorial region, and the second peripheral portion extends over the other half of the equatorial region. 30 Thus, the whole equatorial region is covered with grooves, thereby ensuring a particularly firm and uniform anchoring of the cup in the acetabulum. According to an embodiment of the invention, the number of primary oblique grooves ranges between 12 and 30, preferably between 16 and 26, 35 and in which the number of secondary oblique grooves ranges between 12 and 30, preferably between 16 and 26. Thus, such numbers of primary and secondary oblique grooves ensure a particularly firm anchoring of the cup in the acetabulum. 6318872 1 (GHMatters) P99549.AU LYNT -4 According to an embodiment of the invention, each oblique groove has a depth ranging between 3.5 mm and 5.5 mm. Thus, such an oblique groove depth allows contributing to the anchoring of the cup in the acetabulum. 5 According to a variant of the invention, the inner cavity is greater than the hemisphere, thus allowing to efficiently retain the cotyloid insert. The aforementioned embodiments and variants may be taken alone or according to any technically admissible combination. The present invention will be well understood and its advantages will also 10 appear in light of the following description, given only by way of non limiting example and made with reference to the accompanying drawings in which: - figure 1 is a side view of a cup in compliance with a first embodiment of the invention; - figure 2 is a sectional view, by a meridian plane, of the cup of figure 1; 15 - figure 3 is a view of the opposite side of figure 1; and - figure 4 is a view, similar to figure 3, of a cup in compliance with a second embodiment of the invention. Figures 1 to 3 illustrate a cup 1 for forming a non represented cotyloid implant which is intended to be implanted in an acetabular cavity. This cotyloid 20 implant or cotyle allows replacing the hip joint. The cup 1 has an inner cavity 2 which is suitable for housing a non represented cotyloid insert. In practice, the inner cavity 2 defines a surface greater than a hemisphere, in order to efficiently retain the cotyloid insert. The cup 1 further has an outer surface 4 which is intended to be secured to 25 the acetabulum. The outer surface 4 generally has the shape of a half-spheroid centered on a central axis X4. The outer surface 4 has an equatorial lip 10, an equatorial region 20 and a polar region 30. The equatorial region 20 extends radially protruding with respect to the polar region 30 and with respect to the equatorial lip 10. 30 The equatorial region 20 has a constant height H20 measured in parallel with the central axis X4. The height H20 of the equatorial region 20 is here around 12 mm. The equatorial region 20 has three circular slots or grooves 21, 22 and 23. The circular grooves 21, 22 and 23 are generally parallel and are generally coaxial 35 with the central axis X4. In addition, the equatorial region 20 has oblique slots or grooves 25, which are arranged transversally to the circular grooves 21, 22 and 23. The oblique grooves 25 are here arranged over the entire periphery of the equatorial region 20. 6318872 1 (GHMatters) P99549.AU LYNT -5 The oblique grooves 25 comprise: - primary oblique grooves 25.1 which are oriented on the right and which are positioned on a first peripheral portion 20.1 of the equatorial region 20; and 5 - secondary oblique grooves 25.2 which are oriented on the left and which are positioned on a second peripheral portion 20.2 of the equatorial region 20. The second peripheral portion 20.2 is distinct from the first peripheral portion 20.1. 10 Each circular groove 21, 22 or 23 has a depth P21, measured perpendicularly to the central axis X4, which is here around 1.5 mm. Each circular groove 21, 22 or 23 has a width L21, measured in parallel with the central axis X4, which is here around 0.8 mm. The equatorial lip 10 has a constant height H10 and here around 1.5 15 mm, measured in parallel with the central axis X4. Each primary oblique groove 25.1 forms with the central axis X4, in projection in the meridian plane of the half-spheroid which is the farthest from this primary oblique groove 25.1, a primary angle A25.1 which is here around 15 degrees. The primary oblique grooves 25.1 are oriented according to 20 different primary angles A25.1. Each secondary oblique groove 25.2 forms with the central axis X4, in projection in the meridian plane of the half-spheroid which is the farthest from this secondary oblique groove 25.2, a secondary angle A25.2 which is here around 15 degrees. The secondary oblique grooves 25.2 are oriented 25 according to different secondary angles A25.2. The primary oblique grooves 25.1 are oriented according to a same primary angle A25.1. The secondary oblique grooves 25.2 are oriented according to a same secondary angle A25.2. The first peripheral portion 20.1 extends over one half of the equatorial 30 region 20. The second peripheral portion 20.2 extends over the other half of the equatorial region 20. The number of primary oblique grooves 25.1 here is eighteen and the number of secondary oblique grooves 25.2 here is eighteen. Each oblique groove 25 has a depth P25 which is here around 4.5 35 mm. As shown by figure 3, the cup 1 has a half-slot and fractions of grooves at the junction between the primary oblique grooves 25.1 and the secondary oblique grooves 25.2. 6318872 1 (GHMatters) P99549.AU LYNT -6 Figure 4 illustrates a cup 101 in compliance with a second embodiment of the invention. In as far as the cup 101 is similar to the cup 1, the description of the cup 1 given herebefore in connection with figures 1 to 3 may be transposed to the cup 101, except for the significant differences mentioned hereinafter. 5 A cup 101 component identical or corresponding, by its structure or by its function, to a component of the cup 1 bears the same numerical reference increased by 100. It is thus defined an outer surface 104 with a central axis X1 04, an equatorial lip 110, an equatorial region 120 and a polar region 130, circular groves 121, 122 10 and 123, oblique grooves 125 with primary oblique grooves 125.1 and secondary oblique grooves 125.2. As the comparison between figures 3 and 4 shows, the cup 101 differs from the cup 1, in particular as the cup 101 is without a half-groove at the junction between the primary oblique grooves 125.1 and the secondary oblique grooves 15 125.2. In other words, at this junction, the primary oblique groove 125.1 and the secondary oblique groove 125.2 define a substantially triangular portion, instead of sections of oblique grooves in the case of the cup 1. Thus, the cup 101 is relatively simpler to machine than the cup 1. 20 6318872 1 (GHMatters) P99549.AU LYNT

Claims

1. A cup (1; 101), for cotyloid implant intended to be implanted in an acetabular cavity, the cup (1; 101) having: - an inner cavity (2) suitable for housing a cotyloid insert; and 5 - an outer surface (4; 104) intended to be secured to the acetabulum, the outer surface (4; 104) generally having the shape of a half spheroid centered on a central axis (X4; X104), the outer surface (4; 104) having an equatorial lip (10; 110), an equatorial region (20; 120) and a polar region (30; 130), the equatorial region (20; 120) extending radially protruding 10 with respect to the polar region (30; 130) and with respect to the equatorial lip (10; 101), the equatorial region (20; 120) having a constant height (H20) measured in parallel with the central axis (X4; X104), the equatorial region (20; 120) having: o at least three circular grooves (21, 22, 23; 121, 122, 123) which 15 are generally parallel and which are generally coaxial with the central axis (X4; X104); the cup (1; 101) being characterized in that the equatorial region (20; 120) further has: o oblique grooves (25) arranged transversally to the circular 20 grooves (21, 22, 23; 121, 122, 123) and over all or part of the periphery of the equatorial region (20; 120), the oblique grooves comprising: - primary oblique grooves (25.1; 125.1) which are oriented on the right and which are positioned on a first peripheral portion (20.1) of the equatorial region (20; 120); and 25 - secondary oblique grooves (25.2; 125.2) which are oriented on the left and which are positioned on a second peripheral portion (20.2) of the equatorial region (20; 120), the second peripheral portion (20.2) being distinct from the first peripheral portion (20.1).

2. The cup (1; 101) according to claim 1, wherein the equatorial region 30 (20; 120) has four or five circular grooves (21, 22, 23; 121, 122, 123).

3. The cup (1; 101) according to any of the preceding claims, wherein each circular groove (21, 22, 23; 121, 122, 123) has a depth (P21), measured perpendicularly to the central axis (X4; X104), ranging between 0.5 mm and 1.2 mm, preferably between 0.7 mm and 1.0 mm, and a width 35 (L21), measured in parallel with the central axis (X4; X104), ranging between 0.6 mm and 1.0 mm.

4. The cup (1; 101) According to any of the preceding claims, wherein the equatorial lip (10; 110) has a constant height (H10) measured in parallel 6318872 1 (GHMatters) P99549.AU LYNT -8 with the central axis (X4; X104), and ranging between 0.5 mm and 2.5 mm, preferably between 1.2 mm and 1.8 mm.

5.The cup (1; 101) according to any of the preceding claims, wherein the height (H20) of the equatorial region (20; 120) ranges between 6 mm and 15 mm, 5 preferably ranging between 8 mm and 13 mm.

6. The cup (1; 101) according to any of the preceding claims, wherein each primary oblique groove (25.1; 125.1) forms with the central axis (X4; X104), in projection in the meridian plane of the half-spheroid which is the farthest from said primary oblique groove (25.1; 125.1), a primary angle (A25.1) ranging between 8 10 degrees and 60 degrees, preferably ranging between 10 degrees and 30 degrees; and in which each secondary oblique groove (25.2; 125.2) forms with the central axis (X4; X104), in projection in the meridian plane of the half-spheroid which is the farthest from said secondary oblique groove, a secondary angle (A25.2) ranging 15 between 8 degrees and 60 degrees, preferably ranging between 10 degrees and 30 degrees.

7. The cup (1; 101) according to claim 6, wherein the primary oblique grooves (25.1; 125.1) are oriented according to a same primary angle (A25.1), and wherein the secondary oblique grooves (25.2; 125.2) are oriented according to a 20 same secondary angle (A25.2).

8. The cup (1; 101) according to any of the preceding claims, wherein the first peripheral portion (20.1) extends over one half of the equatorial region (20; 120), and the second peripheral portion (20.2) extends over the other half of the equatorial region (20; 120). 25

9. The cup (1; 101) according to any of the preceding claims, wherein the number of primary oblique grooves (25.1; 125.1) ranges between 12 and 30, preferably between 16 and 26, and in which the number of secondary oblique grooves (25.2; 125.2) ranges between 12 and 30, preferably between 16 and 26.

10. The cup (1; 101) according to any of the preceding claims, wherein each 30 oblique groove (25) has a depth (P25) ranging between 3.5 mm and 5.5 mm. 6318872 1 (GHMatters) P99549.AU LYNT