Implant and drilling template for the treatment of hip dysplasia

Abstract

Implant (1) for treating hip dysplasia by correcting coverage of a head (30) of a femur (31) by an acetabulum (32) and a corresponding drilling template (21) for placement of the implant (1), wherein this implant (1) comprises an abutting fastening member (3) intended to fit against the ilium (34) above the acetabulum (32), wherein this implant (1) comprises a covering extension member (4) intended to cover the head (30) of the femur (31) in extension of the acetabulum (32), wherein the fastening member (3) comprises a standing bone support (7) intended to be inserted in a recess (35) in the ilium (34) and to at least partially absorb a pushing force (39) on the covering extension member (4).

Description

[0001] IMPLANT AND DRILLING TEMPLATE FOR THE TREATMENT OF HIP DYSPLASIA

[0002] The invention concerns an implant for the treatment of hip dysplasia by correcting of a covering of a head of a thighbone, also called femur, by a hip socket, also called acetabulum, and a corresponding drilling template for preparing the placement of the implant.

[0003] The implant includes an abutting fastening member having a support surface designed to fit against the ilium above the acetabulum and with a fastening aperture in this fastening member designed for a fastening means for securing the abutting fastening member to the ilium through the fastening aperture and, preferably, thereby clamping the abutting fastening member between the fastening means and the ilium. Furthermore, the implant comprises a covering extension member designed to fit against tissue around the femoral head with a covering surface and to cover this head in the extension of the acetabulum. In this way, the internal surface of the acetabulum and the covering surface align with each other. Thus, the natural acetabulum and the covering surface of the implant together form a cup-shaped cavity in which the femoral head fits.

[0004] Tissue such as the joint capsule around the femoral head that preferably makes contact with the covering surface is thereby taken into account.

[0005] Further, the invention also concerns a computer-implemented method for designing and manufacturing such an implant and a corresponding drilling template.

[0006] The pelvis is composed of the sacred bone or os sacrum, the tail bone or os coccygis, the left hip or left os coxae and the right hip or right os coxae. The left hip and right hip are each further composed of the left and right iliac bone or os ilium, respectively, the left and right seat bone or ischium, respectively, and the left and right pubic bone or os pubis, respectively. The left and right hip each contain a hip socket or acetabulum, which has an internal surface and forms a cupshaped cavity. The os ilium is located above the acetabulum. The hip joint or articulus coxae connects the thighbone and the hip and contains the acetabulum and a spherical head of the thighbone or femur. The head, also called the femoral head or hip head, fits into the acetabulum which covers this head and in which this head can rotate so that the femur can move in multiple directions. To this end, the acetabulum and the head are provided with a layer of cartilage. This cartilage is not described in further detail in this description. The femoral head and the acetabulum are further surrounded by a joint capsule consisting of connective tissue which produces and contains the synovial fluid. The hip joint is important for the mobility of the femur and for the transmission of forces from the femur to the left or right hip.

[0007] This description and the appended claims relate to both the left and the right hip joint.

[0008] Patients suffering from hip dysplasia show signs of inadequate or incorrect capping of the femoral head by the acetabulum. This may be caused by, for example, a deformity of the acetabulum.

[0009] It may be possible to correct this by providing an implant that extends the capping of the femoral head by the acetabulum. In this way, the femoral head is better enclosed, as is also described, for example, in the international patent application W02017 / 209605.

[0010] For this purpose, the implant is attached to the ilium above the acetabulum by means of screws and it has a covering extension member that encloses the femoral head together with the existing natural acetabulum. The covering extension member is designed to make contact with the joint capsule on its underside and, by performing a kinematic collision analysis of the femur with the implant, it is ensured that the range of motion of the femur in relation to the hip bone is sufficiently large. This ensures better stability of the hip joint. The extension member reduces the pressure on the articular cartilage, pain and limping, and it can prevent (sub)luxation of the hip joint. The implant must be able to withstand relatively high loads here. In particular, the screws which attach the implant to the ilium must be able to withstand relatively high loads. Indeed, there is a risk of fracture occurring over time at the screw heads where the load is high. The invention aims to propose a device and method allowing to remedy these disadvantages. In particular, the invention aims to remedy these disadvantages by proposing an implant and a corresponding drilling template that allow it to withstand such high loads. The invention further aims to propose a method for designing and manufacturing such an implant and a corresponding drilling template.

[0011] To this end, the abutting fastening member includes a bone support standing on the support surface designed to be inserted with a free end into a recess in the ilium above the acetabulum and to at least partially absorb a pushing force on the covering extension member, as claimed in the appended claims.

[0012] Practically, the bone support extends between the fastening aperture and the covering extension member.

[0013] In an advantageous manner, the bone support extends from the support surface to a length that is at least 50% of a width over which the covering surface extends from this support surface. Preferably, this is at least 75%, in particular, at least 100%.

[0014] In a very advantageous manner, the bone support has a free surface having a size that is at least 10% of the size of the covering surface, preferably at least 25%, in particular at least 50%. In this case, the free surface of the bone support is the surface that can make contact with the ilium in the recess for this bone support. When the bone support is brought into this recess in the ilium, the entire free surface of the bone support in this recess will preferably be brought into contact with the ilium.

[0015] In a particularly advantageous manner, the support surface has a gradual continuous transition towards the bone support, with, preferably, a concave surface.

[0016] In particular, the bone support may be elongated, and is, preferably, mainly cylindrical. Thus, the bone support may have a thickness of at least 3 to 5 mm, preferably, at least 5 mm, and which, preferably, corresponds to the diameter and / or the width of a cross-section of the bone support.

[0017] The bone support may also have a rough and / or porous texture where pelvic bone can grow into.

[0018] Preferably, the bone support extends mainly parallel to the covering surface.

[0019] In an interesting manner, the fastening aperture comprises a locking opening with an internal thread for a locking screw, wherein the bone support preferably extends between the locking opening and the covering extension member.

[0020] In an efficient manner, the abutting fastening member is provided with several bone supports and / or several fastening apertures.

[0021] Possibly, the bone support and support surface form one monolithic whole.

[0022] Possibly, also the abutting fastening member and the covering extension member form one monolithic whole.

[0023] In a particularly advantageous manner, the bone support is detachable from the support surface and has another end, opposite the free end, with a contact surface that fits closely into a suitable recess in the support surface.

[0024] The other end opposite the free end preferably tapers in this case.

[0025] Also in this case, the contact surface is preferably concave or convex, and / or conical.

[0026] The invention also concerns a set consisting of the implant and a drilling template corresponding to the implant for preparing the placement of this implant, as also claimed in the appended claims. This drilling template includes an abutting fastening member with a support surface designed to fit against the ilium above the acetabulum. This drilling template may also comprise a covering extension member designed to cap the femoral head in line with the acetabulum, which allows to verify the position of the covering extension member during surgery via intra-operative imaging, before placing the implant. The abutting fastening member has a bone support guide for guiding a bone processing tool, such as a milling cutter, a drill and / or a saw blade, for removing bone material to form the recess in the ilium above the acetabulum which is intended to insert the implant's bone support.

[0027] Advantageously, the abutting fastening member is provided with a fastener guide for guiding a bone processing tool, such as a milling cutter, a drill and / or a saw blade, for removing bone material so as to form a fastener recess in the ilium above the acetabulum designed for the fastening means in order to fix the abutting fastening member of the implant to the ilium. The bone support guide preferably extends below the fastener guide here. Preferably, the bone support guide extends between the fastener guide and the covering extension member.

[0028] In a very advantageous manner, the support surface of the abutting fastening member of the drilling template mainly corresponds to the support surface of the abutting fastening member of the implant.

[0029] In a particularly advantageous manner, the covering extension member of the drilling template mainly corresponds to the covering extension member of the implant.

[0030] In an interesting manner, an extension is provided on the support surface of the drilling template, designed to hook behind the ilium in order to position the drilling template on the ilium, in particular to hook behind the anterior inferior iliac spine of the ilium and / or to hook between the anterior inferior iliac spine and the anterior superior iliac spine of the ilium. The extension allows the drilling template to be positioned more easily and accurately on the ilium. This extension may possibly also be provided on a drilling template that is equipped with a fastener guide but not necessarily with a bone support guide.

[0031] A recess may be provided through the abutting fastening member which is designed for a pin to temporarily secure the drilling template as of the ilium. The implant and the corresponding drilling template for preparing the placement of the implant together form a set for treating hip dysplasia.

[0032] The invention further also concerns a computer-implemented method for designing and manufacturing an implant, as also claimed in the appended claims, which includes:

[0033] - generating a 3D model of at least part of the pelvis with the acetabulum and the ilium above this acetabulum, and of at least part of the / emur with its head;

[0034] - virtually creating and positioning a virtual implant using the 3D model, wherein an abutting fastening member of the implant is provided so that it can fit with a support surface of said fastening member against the ilium above the acetabulum, wherein a covering extension member of the implant is provided so that it can cap the femoral head, thereby preferably considering the thickness of the available cartilage and the joint capsule, wherein a fastening aperture is provided in the abutting fastening member of the implant, designed for a fastening means so as to fix the implant to the ilium through the fastening aperture by means of the fastening means, wherein a bone support is provided standing on the support surface, designed to be inserted into a recess in the ilium above the acetabulum;

[0035] - manufacturing the implant in accordance with the virtual implant.

[0036] Advantageously, the bone support is provided here extending between the fastening aperture and the covering extension member of the implant.

[0037] Preferably, a dimension of the bone support is further determined as a function of a foreseeable pushing force on the covering extension member. In this regard, the dimensions of the bone support may include:

[0038] - the length from the support surface over which the bone support extends;

[0039] - the size of the free surface of the bone support;

[0040] - the diameter and / or width of the cross-section of the bone support;

[0041] - the angle between the covering extension member and the bone support; and / or combinations thereof.

[0042] Preferably, size and position of the covering extension member are virtually determined so that the coverage of the femoral head is increased without hindering any rotational movement of the femur within a desired range by collision of the femur with the covering extension member. This can be done by means of kinematic collision analysis.

[0043] The invention further also concerns a computer-implemented method for designing and manufacturing a drilling template for preparing the implant's fitting, as also claimed in the appended claims, which includes:

[0044] - virtually creating and positioning a virtual drilling template using the 3D model, wherein an abutting fastening member of the drilling template is provided so that it can fit against the ilium above the acetabulum with a support surface of said fastening member, wherein a covering extension member of the drilling template is possibly provided so that it can cap the femoral head, wherein the abutting fastening member of the drilling template includes at least one bone support guide for guiding a bone processing tool for removing bone material so as to form a recess in the ilium above the acetabulum designed for the bone support of the implant;

[0045] - manufacturing the drilling template in accordance with the virtual drilling template.

[0046] Advantageously, a fastener guide is provided in the abutting fastening member of the drilling template for guiding a bone processing tool for removing bone material so as to form a fastener recess in the ilium above the acetabulum designed for a fastening means to fix the implant to the ilium with the fastening means, and, preferably, the bone support guide is provided extending below the fastener guide. Preferably, the bone support guide is provided extending between the fastener guide and the covering extension member of the drilling template.

[0047] In particular, the support surfaces of the implant and the drilling template are provided so that they substantially correspond.

[0048] Very particularly, the covering extension members of the implant and the drilling template are provided so that they substantially correspond.

[0049] In a very advantageous way, this method includes:

[0050] - generating the 3D model of at least a part of the / emurwith the head and at least a part of the ilium with the acetabulum, and including the anterior inferior iliac spine and, preferably, the anterior superior iliac spine of the ilium;

[0051] - providing an extension of the supporting surface of the drilling template as a reference for positioning the drilling template on the ilium, wherein said extension hooks behind the ilium, in particular behind the anterior inferior iliac spine and, preferably, between the anterior inferior iliac spine and the anterior superior iliac spine.

[0052] Other particularities and advantages of the invention will become apparent from the following description of some specific embodiments of the device and method according to the invention. This description is given by way of example only and does not limit the scope of the protection claimed; the reference numbers used hereinafter relate to the figures added hereto.

[0053] Figure 1 is a schematic perspective view of an implant according to a first embodiment of the invention with mainly cylindrical bone supports.

[0054] Figures 2, 3 and 4 are schematic perspective views of a drilling template for the implant from Figure 1, fitted on the ilium. Figure 5 is a schematic perspective view of the ilium with recesses for placing the implant from Figure 1.

[0055] Figure 6 is a schematic perspective view of the implant from Figure 1 attached to the ilium.

[0056] Figures 7 to 10 are schematic perspective views of an implant according to a second embodiment of the invention with a wing-shaped bone support.

[0057] Figures 11 and 12 are schematic perspective views of a drilling template for the implant from Figures 7 to 10.

[0058] Figures 13 and 14 are schematic perspective views of a drilling template from Figures 11 and 12, fitted on the ilium.

[0059] Figure 15 is a schematic perspective view of the ilium with recesses for placing the implant from Figures 7 to 10.

[0060] Figure 16 is a schematic perspective view of the implant from Figures 7 to 10 attached to the ilium.

[0061] Figure 17 is a schematic perspective view of an implant according to a third embodiment of the invention with detachable bone supports.

[0062] Figure 18 is a schematic perspective view of an implant according to a fourth embodiment.

[0063] Figure 19 is a schematic view of a diagram for a left hip joint in which the radial coverage of the femoral head by the acetabulum is shown for a femoral head coverage analysis.

[0064] Figure 20 is a schematic view of a diagram as in Figure 19 for a left hip joint with an implant according to the invention in which the radial coverage of the femoral head by the acetabulum and the implant is shown for a femoral head coverage analysis.

[0065] In the various figures, the same reference numbers refer to the same or analogous elements.

[0066] The invention generally concerns an implant for the treatment of hip dysplasia, a corresponding drilling template and a method for designing and manufacturing the implant and drilling template. The implant comprises a covering extension member for the acetabulum to increase the coverage of the femoral hip head by the acetabulum. By means of an abutting fastening member, the implant is intended to be secured to the ilium above the acetabulum with one or several fastening means, such as screws, so that the covering extension member extends with a covering surface in the extension of the natural acetabulum over the femoral head. Preferably, the abutting fastening member also fits against the acetabulum. In this way, the internal surface of the natural cup-shaped cavity of the acetabulum is increased by the covering surface of the extension member. The covering surface thus connects to the natural cup-shaped cavity of the acetabulum to form a larger cup-shaped cavity in which the femoral head fits, thus capping a larger part of the femoral head. The implant is provided with at least one bone support that is intended to extend into a recess in the ilium to relieve the fastening means when an upward force is exerted by the femoral head on the extension member. Preferably, the bone support extends between the fastening means and the extension member. Thus, the implant preferably has an underside with the covering extension member, with the bone support above it and further with the fastening means above this bone support.

[0067] A drilling template is provided for placing the implant, whereby this drilling template also includes a fastening member and a covering member. Preferably, the fastening member and the covering member substantially correspond to those of the implant. The drilling template allows a bone processing tool to be guided while removing material from the ilium to make the recess for the bone support in the ilium.

[0068] According to a first embodiment of the implant, shown in Figures

[0069] 1 and 6, it comprises an abutting fastening member 3 having a support surface 2 designed to fit against the ilium 34 above the acetabulum 32. The support surface

[0070] 2 has a shape that fits on the surface of the ilium and is preferably provided with an open, rough and / or porous surface texture 43 that allows bone ingrowth.

[0071] The abutting fastening member 3 includes three fastening apertures 5 designed for fastening means 6 to fix the abutting fastening member

[0072] 3 through the fastening apertures 5 to the ilium 34 and, preferably, thereby clamping the abutting fastening member 3 between the fastening means 6 and the ilium 34.

[0073] The fastening apertures 5 may possibly form locking apertures 14 with an internal thread 15. The fastening means 6 may then include a locking screw 16, provided at the head with an external thread that fits on the internal thread 15. Different types of fastening apertures 5 or 14 may possibly be provided with or without the internal thread 15.

[0074] According to a variant embodiment, the abutting fastening member 3 may be provided with more or fewer fastening apertures 5, but at least one fastening aperture 5 is always provided. These apertures 5 may or may not contain locking apertures 14.

[0075] A locking aperture 14 is provided together with a locking screw 16 to ensure that the abutting fastening member 3 is not clamped too hard against the ilium 34 and to ensure proper force transfer from the implant to the bone. By means of locking screws 16, for example, the support surface 2 can be fixed at a certain distance from the femur 34 and a good rigid connection can be guaranteed as well, even in the event that the ilium bone would show a small resorption after surgery. This technique is known as such to persons skilled in the art.

[0076] The implant 1 further comprises a covering extension member 4 designed to fit with a covering surface 42 against tissue 44 around the head 30 of the femur 31 and to cap this head 30 in the extension of the acetabulum 32, as shown in Figure 6. The covering surface 42 thus forms, together with the natural acetabulum 32, the cup-shaped cavity in which the head 30 fits, and the surface 42 thus increases the coverage of the head 30. In this respect, the dimensions and shape of tissue 44 such as cartilage and joint capsule, located between and around the head 30 and the acetabulum 32, are considered. Thus, the covering extension member 4 does not make any direct contact with the head 30 of the femur 31, but the force transmission between the extension member 4 and the head 30 of the femur 31 takes place through the tissues 44, with the cartilage of the head 30 sliding relative to the joint capsule against which the covering extension member is pressed. The covering surface 42 has a width 40 from the support surface

[0077] 2 to a free end 48.

[0078] The position of the covering surface 42 relative to the support surface 2 is of course related to the position of the acetabulum 32 in the ilium 34, but it can generally be assumed that the covering surface 42 is mainly transverse to the support surface 2. Depending on the specific anatomy of the patient and how the natural acetabulum is formed, the covering surface 42 may extend mainly laterally in some cases, extend laterally-anteriorly in some cases and / or even extend partially posteriorly.

[0079] The femur 31 exerts a pushing force 39 on the acetabulum 32 via the head 30 and through the joint capsule also on the covering surface 42 of the extension member 4. To absorb this pushing force 39 at least partially, one or more standing bone supports 7 are provided on the support surface 2.

[0080] In this first embodiment, the bone supports 7 are elongated and mainly cylindrical. They have a diameter corresponding to a thickness 47 of at least 3 to 5 mm. Furthermore, they have a length 41 which amounts to the distance between the support surface 2 and a free end 8. Thus, these bone supports 7 form standing pins 7 which are intended to extend with their free ends 8 into a recess 35 in the ilium 34 above the acetabulum 32. The bone supports 7 further have a free surface designed to fit against the ilium 34 in the recess 35.

[0081] The free end 8 of the bone support 7 and the free end 48 of the covering surface 42 of the extension member 4 are turned away from each other.

[0082] The bone support 7 preferably extends substantially transversely to the support surface 2 and / or preferably substantially parallel to the covering surface 42. Since the shape of the support surface 2 corresponds to the shape of the surface of the ilium 34 against which it is to fit, and the shape of the covering surface 42 depends on the shape of the head 30 of the femur 31 and the tissue 44 surrounding the latter against which it is to fit, these surfaces 2 and 42 are not flat but they have curvatures. Consequently, the bone support 7 may not be transverse or parallel with respect to the full surfaces 2 and 42. The term substantially should therefore be understood as for a large part of the surface 2 and 42.

[0083] Without the bone supports 7, the fastening means 6 would absorb most of the pushing force 39 on the extension member 4, which may result in static or dynamic overload resulting in fracture of the fastening means 6.

[0084] In this first embodiment, the bone supports 7 preferably extend between the fastening apertures 5 and the covering extension member 4. These fastening apertures 5 are therefore located above the bone supports 7. As a result, the fastening means 6 are maximally relieved. It is of course not excluded for fastening apertures to be provided below and / or between the bone supports 7.

[0085] The force 39 exerted by the head 30 on the extension member 4 depends, among other things, on the size of the covering surface 42 and / or the width 40 over which this surface 42 extends between the support surface 2 and a free end 48.

[0086] The shape and size of the bone support 7 is determined depending on the foreseeable load, considering the ilium 34 in which this bone support 7 must extend in the recess 35.

[0087] The support surface 2 preferably has a gradual continuous transition 12 towards the bone support 7 to avoid stress concentrations at the transition 12. This transition 12 therefore preferably has a smooth surface with a curved shape, without any sharp edges or corners, such as, for example, in the case of a rounding (radius). Thus, in this embodiment, said transition 12 of the support surface 2 preferably has a hollow or so-called concave surface. This surface may also be conical, such as, for example, in the case of a chamfer.

[0088] In order to allow pelvic bone to grow together with the bone support 7, the free surface of this bone support 7 is preferably provided with an open, rough and / or porous surface texture 46.

[0089] Optionally, the even surface of the transition 12 may contain the open, rough and / or porous texture 43 which continues uninterruptedly and transitions into the open, rough and / or porous texture 46 of the surface of the bone support 7.

[0090] Further, the implant preferably forms a single monolithic unit comprising the covering extension member 4 with the covering surface 42 and the abutting fastening member 3 with the bone supports 7 and the support surface 2.

[0091] A corresponding drilling template 21 for preparing the placement of this implant 1 according to the first embodiment is shown in Figures 2 to 4.

[0092] The drilling template 21 includes an abutting fastening member 23 with a support surface 22 designed to fit against the ilium 34 above the acetabulum 32. In this first embodiment, the support surface 22 of the drilling template 21 preferably substantially corresponds to the support surface 2 of the abutting fastening member 3 of the implant 1 of this embodiment.

[0093] The drilling template 21 further comprises, below the abutting fastening member 23, a covering extension member 24 designed to cover the head 30 of the femur 31 as an extension of the acetabulum. Preferably, the covering extension member 24 of this drilling template 21 substantially corresponds to the covering extension member 4 of the implant 1 according to this embodiment. In a variant, the drilling template 21 could also be made without this covering extension member 24 which mainly serves for visualising the covering extension member 4 of the implant 1 to be provided.

[0094] The abuttingfastening member 23 ofthe drilling template 21 has a bone support guide 27 for guiding a bone processing tool 45, such as a milling cutter, a drill and / or a saw blade, for removing bone material to form the recess 35 in the ilium 34 above the acetabulum 32 designed for inserting the bone support 7 of the implant 1 in. Thus, the recess 35 may consist of a drill hole, a series of contiguous adjacent drill holes or a milled-out or sawn-out slot adapted to the bone support 7.

[0095] The drilling template 21 may optionally be provided with a fastener guide 25 in the abutting fastening member 23 for guiding a bone processing tool such as a milling cutter, a drill and / or a saw blade, for removing bone material to form a fastener recess 36, such as a drill hole, in the ilium 34 above the acetabulum 32 that is designed for the fastening means 6 in order to attach the abutting fastening member 3 of the implant 1 to the ilium 34. However, this drill hole 36 could possibly be made directly through the opening 5 in the implant 1. Self-drilling screws may also be used. Thus, it is not necessary to provide a borehole 36 before placing the implant 1.

[0096] Just as the bone supports 7 at the implant 1, the bone support guides 27 extend below the optional fastener guide 25, i.e. between the optional fastener guide 25 and the covering extension member 24. Of course, the fastener guide 25 being either or not provided, as well as its location, are tailored to the implant 1 whose placement is being prepared.

[0097] The drilling template 21 is preferably provided with an extension 28 on the support surface 22 designed to hook behind the ilium 34. This allows the drilling template 21 to be unambiguously positioned on the ilium 34 in a simple manner. Thus, this extension 28 can be provided to hook behind the anterior inferior iliac spine 37 of the ilium 34 and / or between the anterior inferior iliac spine 37 and the anterior superior iliac spine 38 of the ilium 34. Indeed, without the presence of the extension 28 hooking behind the ilium, the drilling template 21 might have too much mobility in relation to the ilium surface against which it rests, as the existing soft tissues and fluid make precise positioning difficult.

[0098] The drilling template 21 according to this embodiment is preferably also provided with at least one recess 20 for a pin 29 to temporarily fix the drilling template 21 as of the ilium 34. This may, for example, allow verification of the position of the drilling template 21 and, in particular, of the covering extension member 24 by means of intra-operative imaging before the recesses 35 for the bone supports 7 are being made in the bone.

[0099] A second embodiment of the implant 1, shown in Figures 7 to 10, differs from the first embodiment in that the bone support 7 is formed by a wing 7 standing on the support surface 2. This wing 7 has a length 41 as of the support surface 2 to the free end 8. The wing 7 further has a thickness 47 and a width 49. The cross-section of this bone support 7 forms a rectangle. The surface of the wing 7 preferably has, at least in part, a rough and / or porous texture 46 that allows ingrowth of bone.

[0100] The dimensions of the wing 7 are preferably determined as a function of the foreseeable load on the covering surface 42 and, of course, also the dimensions of the ilium 34 in which the recess 35 is to be provided.

[0101] The foreseeable load on the covering surface 42 may depend on, among other things, the size of this surface 42, the position of the surface 42 in relation to the head 30 of the femur 31 and possibly also on the physical characteristics and / or activities of the patient.

[0102] The corresponding drilling template 21 according to this second embodiment has a bone guide 27 forming a slot to guide a saw blade or a milling cutter or containing a series of adjacent cylindrical guides for a bone processing tool 45, such as a milling cutter, a drill and / or a saw blade. This allows a recess 35 in the shape of a slot to be provided in the ilium 34 for the bone support 7. Specifically, the recess 35 may be formed by providing a number of parallel contiguous drill holes.

[0103] A third embodiment of the implant 1, shown in Figure 17, differs from the first embodiment in that the bone supports 7 are detachable from the support surface 2. In this way, it remains possible to remove the implant 1 with the covering extension member 24 more easily in case of complications or in the event of a subsequent fitting of a total hip prosthesis, while the osseointegrated bone supports 7 can remain in the ilium.

[0104] Opposite the free end 8, these bone supports 7 have another end 9 with a contact surface 10 that may fit closely into a suitable recess 11 in the support surface 2.

[0105] The transition 12 from the support surface 2 to the surface of the bone support 7 is preferably gradual and continuous when the bone support 7 is fit in the recess 11. Here, the length 41 of said bone support 7 is the distance over which the bone support 7 with its end 8 extends as of the support surface 2 when said bone support 7 is fitted in the recess 11. The end 9 opposite the free end 8 of the bone support 7 to be inserted into the recess 11 is preferably tapered. This possibly allows the support surface 2 to be easily detached from the bone supports 7 if the implant 1 ever needs to be removed, while these bone supports 7 may possibly remain in place.

[0106] The contact surface 10 may have a concave or convex, conical, concave-conical or convex-conical design in this case. The recess 11 is adapted thereto, so that the end 9 with the contact surface 10 can fit closely therein.

[0107] The recess 11 may possibly run straight through the abutting fastening member 3 or it may form a blind hole. If the bone support 7 narrows towards the end 9, it can be inserted in the recess 11 on the side of the support surface 2 and this recess can be made as a blind hole. This option allows optimal transmission to the bone support 7 of forces acting on the covering surface 42.

[0108] A fourth embodiment of the implant 1, shown in Figure 18, differs from the third embodiment in that the recess 11 for the other end of the bone support 9 runs straight through the abutting fastening member 3 and is provided as a bone support guide for guiding a bone processing tool, such as a milling cutter, a drill and / or a saw blade, for removing bone material to form the recess in the ilium above the acetabulum for the bone support 7. Thus, the implant 1 itself can function as a drilling template. Furthermore, an extension 28 may also be provided on the support surface 2 designed to hook behind the ilium to position the implant 1 on the ilium. In this case, said extension 28 may be connected to the support surface 2 via a thin connection, which may be cut as such by the surgeon after placing the implant 1, after which the extension 28 can be removed from the support surface 2.

[0109] In variations of the above embodiments, not shown in the figures, one or more bone supports 7 may thus be provided and / or one or more fastening means 6 may be provided.

[0110] In general, the shape and function of the fastening means 6 and the bone support 7 are different.

[0111] The bone support 7 is designed, together with the support surface 2, to allow the implant 1 with its abutting fastening member 3 to rest against the underlying cortical and trabecular bone of the ilium 34 and to thus absorb an upward pushing force 39, or also the vertical component of a force, on the covering surface 42 of the extension member 4 and to divert it to the ilium 34. In contrast, the bone support 7, especially before it has grown into the bone, offers little resistance to a lateral tensile force directed along its axial direction, for example.

[0112] The fastening means 6 are designed to fix the abutting fastening member 3 of the implant 1 to the ilium 34 above the acetabulum 32, thereby preferably clamping the abutting fastening member 3 between the head of the fastening means 6 and the ilium 34, and to thus, for example, absorb a tensile force, or also the lateral component of a force, on the covering extension member 4 of the implant 1.

[0113] The implant 1 and the corresponding drilling template 21 are preferably designed and manufactured using a computer-implemented method in which a digital 3D model of at least part of the femur 31 with, preferably, the head 30 and at least part of the ilium 34 with the acetabulum 32 is generated. The 3D model can be based on data obtained by medical imaging techniques known per se, such as, for example, an X-ray scan, a CT scan and / or an MRI scan. Based on this imaging, the coverage of the hip head 30 by the acetabulum 32 can be determined and analysed. The anatomy of the cartilage and joint capsule can be taken into consideration by either estimating them based on average population data or by segmenting them based on, for example, an MRI scan.

[0114] A desired coverage of the hip head 30 can subsequently be determined by comparison with, for example, the coverage in an average population. The covering surface 42 of the implant 1 can be designed so as to approximate the desired coverage as closely as possible. In doing so, it should be taken into consideration that the implant 1 may not cause any undesirable obstruction to the mobility of the femur 31. Thus, the implant 1 can be virtually positioned on the ilium 34, taking into account the thickness of the cartilage and the joint capsule. Also, the movement of the femur 31 by rotation of the head 30 in the acetabulum 32 can then be simulated. Schematically, this can be represented, for exam pie, in a diagram as shown in Figures 19 and 20 for, say, a left hip joint. In this bell curve diagram, the radial coverage, measured relative to the vertical direction 53 in an upright person, or also the coverage of the hip head 30 by the acetabulum 32 is shown in different directions, i.e. lateral 54, medial 55, anterior 56 and posterior 57. In the lateral direction, the value of the curve corresponds to the known 'Lateral Centre Edge' (LCE) angle, which is classically derived from an X-ray image increased by 90 degrees.

[0115] Line 50 represents the coverage in an average population. Line 51 represents the coverage for a patient suffering from hip dysplasia. Line 52 represents the coverage for the same patient in which the coverage of the head 30 by the acetabulum 32 was increased by that of the virtual implant 1. Based on virtually designed and positioned implants 1, mobility analyses can be performed that analyse the range of motion of the femur 31 (e.g.: flexion / extension, abduction / adduction, internal and external rotation, range of motion). This can avoid the presence of the implant 1 leading to unwanted interference (impingement) with the femur 31 and / or with the attached muscles and / or tendons. In this way, different positions and sizes of the implant 1 can be compared and analysed, for example, with respect to their more optimal extension of the coverage of the femoral head 30. Thus, a person skilled in the art can determine the optimal dimensions and position of the covering surface 42 and in doing so also of the entire implant 1.

[0116] Furthermore, the virtual implant 1 is provided with one or more bone supports 7 and the stress in the material of the bone supports 7 is preferably calculated as well, for example, via a finite element analysis, known to a person skilled in the art (or via a simplified calculation), based on the expected force 39 on the covering surface 42. In this way, the dimensions of the bone supports 7 and their number may be adapted to the foreseeable force exerted on them based on the expected activity of the specific patient.

[0117] The dimensions that can be adjusted include, among others, the length 41 as of the support surface 2 over which the bone support 7 extends, the size of the free surface of the bone support 7, the diameter and / or width 47 of the cross-section of the bone support 7, the angle between the covering extension member 4 and the bone support 7. The free surface of the bone support 7 is the surface that can make contact with the ilium 34 in said recess 35. When the bone support 7 extends into the recess 35 in the ilium 34, a larger free surface area of this bone support 7 can, for example, ensure greater contact with the ilium 34 and better distribution and / or transmission of forces to the ilium 34.

[0118] In addition to the implant 1, a corresponding drilling template 21 with an abutting fastening member 23 and a covering extension member 24 can also be virtually designed in an analogous manner to prepare for the implant 1 being fitted. The drilling template 21 is of course specifically adapted to the designed implant 1 in this case.

[0119] In this case, a bone support guide 27 is provided for guiding a bone processing tool, such as a milling cutter, a drill and / or a saw blade, for removing bone material to form the recess 35 in the ilium 34 above the acetabulum 32 designed for the bone support 7 of the implant 1.

[0120] A fastener guide 25 may also be provided for guiding a bone processing tool, such as a milling cutter, a drill and / or a saw blade, for removing bone material to form a fastener recess 36 such as a drill hole in the ilium 34 that is designed for a fastening means 6 to fix the implant 1 to the ilium 34.

[0121] The generated 3D model preferably includes the anterior inferior iliac spine 37 and, preferably, also the anterior superior iliac spine 38 of the ilium 34. The drilling template 21 can then possibly be provided with an extension 28 of the support surface 22 of the abutting fastening member 23 as a reference to position the drilling template 21 on the ilium 34. The extension 28 thereby hooks behind the ilium 34, in particular behind the anterior inferior iliac spine 37 and, preferably, between the anterior inferior iliac spine 37 and the anterior superior iliac spine 38. This makes it easy to position the drilling template 21 correctly and unambiguously on the ilium 34.

[0122] The implant 1 and drilling template 21 can be made of materials known as such by a person skilled in the art. This may be, for example, titanium, a titanium alloy or PEEK / PEKK. The underside of the covering surface 42 can also be made of a material with lower rigidity than the rest of the implant. For example, the underside of the covering surface 42 can be made of a high-density polyethylene or ultra-high-density polyethylene material or of a polyurethane material, while the rest of the implant 1 consists of, for example, titanium. This ensures the strength and osseointegration of the implant, while the softer material on the underside of the covering surface 42, which makes contact with the joint capsule and potentially makes contact with the cartilage of the femoral head 30 in the event of damage to the capsule, provides cushioning and a reduction in peak forces on the implant, while also ensuring a reduced likelihood of cartilage damage should the underside of the covering surface 42 make contact with the cartilage of the femoral head 30.

[0123] Naturally, the invention is not limited to the devices and methods described above and the embodiments thereof represented in the accompanying figures. Thus, the various features of these embodiments and variants can be mutually combined.

Claims

CLAIMS1. Implant (1) fortreating hip dysplasia by correcting coverage of a head (30) of a femur (31) by an acetabulum (32), wherein this implant (1) comprises an abutting fastening member (3) with a support surface (2) designed to fit against the ilium (34) above the acetabulum (32), and having a fastening aperture (5) in this fastening member (3) designed for a fastening means (6) to fix the abutting fastening member (3) through the fastening aperture (5) to the ilium (34), thereby preferably clamping the abutting fastening member (3) between the fastening means (6) and the ilium (34), wherein this implant (1) further comprises a covering extension member (4) designed to fit together with a covering surface (42) against tissue (44) around the head (30) of the femur (31) and to cover this head (30) in extension of the acetabulum (32), characterised in that the abutting fastening member (3) comprises a bone support (7) standing on the support surface (2) designed to be inserted with a free end (8) in a recess (35) in the ilium (34) above the acetabulum (32) and to at least partially absorb a pushing force (39) on the covering extension member (4).

2. An implant according to claim 1, wherein the covering surface (42) extends as of the support surface (2) up to a width (40) and the bone support (7) extends as of this support surface (2) up to a length (41), wherein the length(41) of the bone support (7) is at least 50% of the width (40) of the covering surface(42), preferably at least 75%, in particular at least 100%.

3. An implant according to claim 1 or 2, wherein the bone support (7) has a free surface with a size that is at least 10% of the size of the covering surface (42), preferably at least 25%, in particular at least 50%.

4. An implant according to any of claims 1 to 3, wherein the bone support (7) extends between the fastening aperture (5) and the covering extension member (4).

5. An implant according to any of claims 1 to 4, wherein the support surface (2) has a gradual continuous transition (12) towards the bone support (7) and wherein this transition (12) preferably has a concave surface.

6. An implant according to any of claims 1 to 5, wherein the bone support (7) is elongated and preferably mainly cylinder-shaped.

7. An implant according to any of claims 1 to 6, wherein the bone support (7) has a thickness (47) of at least 3 to 5 mm, preferably at least 5 mm, and which preferably corresponds to a diameter and / or a width of a cross-section of the bone support (7).

8. An implant according to any of claims 1 to 7, wherein the bone support (7) has a rough and / or porous surface texture (46) that allows pelvic bone to grow in.

9. An implant according to any of claims 1 to 8, wherein the bone support (7) extends mainly parallel to the covering surface (42).

10. An implant according to any of claims 1 to 9, wherein the fastening aperture (5) includes a locking opening (14) with internal thread (15) for a locking screw (16), wherein the bone support (7) preferably extends between the locking opening (14) and the covering extension member (4).

11. An implant according to any of claims 1 to 10, wherein the abutting fastening member (3) is provided with several bone supports (7) and / or several fastening apertures (6).

12. An implant according to any of claims 1 to 11, wherein the bone support (7) and the support surface (2) form one monolithic whole.

13. An implant according to any of claims 1 to 12, wherein the abutting fastening member (3) and the covering extension member (4) form one monolithic whole.

14. An implant according to any of claims 1 to 11, wherein the bone support (7) is detachable from the support surface (2) and wherein the bone support (7) has, opposite its free end (8), another end (9) with a contact surface (10) that fits closely into a matching recess (11) in the support surface (2).

15. An implant according to claim 14, wherein the other end (9) opposite the free end (8) tapers.

16. An implant according to claim 14 or 15, wherein the contact surface (10) is hollow or convex and / or conical.

17. An implant according to any of claims 1 to 16, wherein an extension (28) is provided on the support surface (2) which is designed to hook behind the ilium (34) so as to position the implant (1) on the ilium (34), in particular to hook behind the anterior inferior iliac spine (37) of the ilium (34) and / or between the anterior inferior iliac spine (37) and the anterior superior iliac spine (38) of the ilium (34).

18. A set of an implant according to any of claims 1 to 17 with a drilling template (21) for preparing the placement of the implant (1), wherein this drilling template (21) comprises an abutting fastening member (23) with a support surface (22) designed to fit against the ilium (34) above the acetabulum (32), wherein the abutting fastening member (23) has a bone support guide (27) for guiding a bone processing tool (45) for removing bone material to form the recess (35) in the ilium (34) above the acetabulum (32) designed for inserting the bone support (7) of the implant (1) in.

19. A set according to claim 18, wherein the drilling template (21) comprises a covering extension member (24) designed to cover the head (30) of the femur (31) in extension of the acetabulum.

20. A set according to claim 19, wherein the covering extension member (24) of the drilling template (21) substantially corresponds to the covering extension member (4) of the implant (1).

21. A set according to any one of claims 18 to 20, wherein the support surface (22) of the abutting fastening member (23) of the drilling template (21) substantially corresponds to the support surface (2) of the abutting fastening member (3) of the implant (1).

22. A set according to any one of claims 18 to 21, wherein the abutting fastening member (23) is provided with a fastener guide (25) for guiding a milling cutter, a bone processing tool (45) for removing bone material to form afastener recess (36) in the ilium (34) above the acetabulum (32) designed for the fastening means (6) so as to fix the abutting fastening member (3) of the implant (1) to the ilium (34), wherein the fastener guide (25) is preferably provided such that the bone support (7) of the implant (1) must extend between the fastening means (6) and the covering extension member (4) of the implant (1).

23. A set according to any one of claims 18 to 22, wherein an extension (28) is provided on the support surface (22) of the drilling template (21) designed to hook behind the ilium (34) so as to position the drilling template (21) on the ilium (34), in particular to hook behind the anterior inferior iliac spine (37) of the ilium (34) and / or between the anterior inferior iliac spine (37) and the anterior superior iliac spine (38) of the ilium (34).

24. A computer-implemented method for designing and manufacturing an implant (1) for treating hip dysplasia by correcting the coverage of a head (30) of a femur (31) by an acetabulum (32), wherein this method comprises:- generating a 3D model of at least part of the pelvis (33) with the acetabulum (32) and the ilium (34) above this acetabulum (32) and of at least part of the femur (31) with the head (30);- virtually creating and positioning a virtual implant (1) using the 3D model, wherein an abutting fastening member (3) of the implant (1) is provided so that it can fit together with a support surface (2) of this fastening member (3) against the ilium (34) above the acetabulum (32), wherein a covering extension member (4) of the implant (1) is provided with a covering surface (42) so that it can cover the head (30) of the femur (31) in extension of the acetabulum (32), wherein a fastening aperture (5) is provided in the abutting fastening member (3) of the implant (1), designed for a fastening means (6) so as to fix the implant (1) to the ilium (34) through the fastening aperture (5) with the fastening means (6),wherein a bone support (7) is provided standing on the support surface (2), designed to be inserted in a recess (35) in the ilium (34) above the acetabulum (32);- manufacturing the implant (1) in accordance with the virtual implant (1).

25. A computer-implemented method according to claim 24, wherein the bone support (7) is provided extending between the fastening aperture (5) and the covering extension member (4) of the implant (1).

26. A computer-implemented method according to claim 24 or 25, wherein a dimension of the bone support (7) is determined as a function of a pushing force (39) to be expected on the covering extension member (4).

27. A computer-implemented method according to claim 26, wherein the dimensions of the bone support (7) comprise:- the length (41) as of the support surface (2) over which the bone support (7) extends;- the size of the surface of the bone support (7);-the diameter and / or width (47) of the cross-section of the bone support (7);- the angle between the covering extension member (4) and the bone support (7), and / or combinations thereof.

28. A computer-implemented method according to any one of claims 24 to 27, wherein size and position of the covering extension member (4) are virtually determined so as to increase the coverage of the head (30) of the femur (31) without hindering any rotational movement of the femur (31) within a desired range by collision of the femur (31) with the covering extension member (4).

29. A computer-implemented method according to any one of claims 24 to 28, further comprising designing and manufacturing a drilling template (21) to prepare placement of the implant (1), said method comprising:-the virtual creation and positioning of a virtual drilling template(21) using the 3D model,wherein an abutting fastening member (23) of the drilling template (21) is provided so that it can fit together with a support surface (22) of this fastening member (23) against the ilium (34) above the acetabulum (32), wherein at least one bone support guide (27) is provided in the abutting fastening member (23) of the drilling template (21) for guiding a bone processing tool (45) for the removal of bone material so as to form a recess (35) in the ilium (34) above the acetabulum (32) designed for the bone support (7) of the implant (1);- manufacturing the drilling template (21) in accordance with the virtual drilling template (21).

30. A computer-implemented method according to claim 29, wherein a covering extension member (24) of the drilling template (21) is provided to cover the head (30) of the femur (31).

31. A computer-implemented method according to claim 30, wherein the covering extension members (4, 24) of the implant (1) and the drilling template (21) are provided so that they substantially correspond.

32. A computer-implemented method according to any one of claims 29 to 31, wherein the support surfaces (2, 22) of the implant (1) and the drilling template (21) are provided so that they substantially correspond.

33. A computer-implemented method according to any one of claims 29 to 32, wherein a fastener guide (25) is provided in the abutting fastening member (23) of the drilling template (21) for guiding a bone processing tool (45) for the removal of bone material so as to form a fastener recess (36) in the ilium (34) above the acetabulum (32) designed for a fastening means (6) to fix the implant (1) to the ilium (34) with the fastening means (6), and wherein a fastener guide (25) is preferably provided so that the bone support (7) of the implant (1) must extend between the fastening means (6) and the covering extension member (4) of the implant (1).

34. A computer-implemented method according to any one of claims 29 to 33, wherein this method comprises:- generating the 3D model of at least part of the femur (31) with the head (30) and at least part of the ilium (34) with the acetabulum (32), and including the anterior inferior iliac spine (37) and preferably the anterior superior iliac spine (38) of the ilium (34); - providing an extension (28) of the support surface (22) of the drilling template (21) as a reference for positioning the drilling template (21) on the ilium (34), wherein this extension (28) hooks behind the ilium (34), in particular behind the anterior inferior iliac spine (37) and preferably between the anterior inferior iliac spine (37) and the anterior superior iliac spine (38).

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