BONE PLATE, SURGICAL SETS AND RECONSTRUCTION SETS

Description

[0001] The present invention relates to bone plates according to the preamble of claim 1. Bone screws and surgical sets containing such bone plates and bone screws are also described and claimed.

[0002] Such bone plates can be used to bridge a bone defect or to treat a fracture. In particular, the invention relates to bone plates for the reconstruction or trauma treatment of a human lower jaw.

[0003] The aspect of the invention relates to a bone plate containing at least one opening for receiving at least one bone screw, wherein the opening penetrates the bone plate along a longitudinal axis from an upper side to an opposite lower side, wherein the opening at the upper side opens into a first receiving area which is designed to receive and fix a locking element of a bone screw in a first direction.

[0004] A bone plate with these features of the generic term is known from WO 2004 / 086990 A1.

[0005] Another bone plate is known from US 2009 / 281543 A1.

[0006] When treating unstable comminuted fractures, during reconstruction with bone grafts, and especially when bridging bone defects without bone grafts, stable bone plates are required to safely absorb the loads occurring in the defect area. A generic bone plate for a human lower jaw is known, for example, from WO 01 / 82809. Such plates can be used, for example, to reinforce weakened, atrophied bone structures of a lower jaw. Such bone structures can arise, for example, during the removal of a tumor or as a result of an injury, such as a gunshot wound. The bone plate must be able to withstand the daily stresses and strains that occur, for example, during chewing or swallowing, over a long period of time. To prevent the bone plate from noticeably bending, it must exhibit a certain degree of rigidity.For this purpose, a hard material is usually used, such as grade 4 titanium. Titanium of this grade is, on the one hand, very hard and therefore stiff when bent, but on the other hand, it is also relatively brittle.

[0007] However, the anatomy of human bones, and in particular of the human lower jaw, varies greatly from individual to individual. For example, the distance of the jaw angle, formed between the ascending ramus and the horizontal ramus, from the center of the chin varies depending on the patient's age, height, and gender. Due to the individual variations in bone shape, particularly in the human lower jaw, anatomically moldable plates or specially manufactured patient-specific plates are required. From a practical perspective, it is therefore almost impossible for a hospital or surgeon to keep a pre-formed, suitable bone plate in stock for every anatomy. Instead, the surgeon must adapt the bone plate to the individual patient anatomy by cutting and bending.

[0008] To date, various therapeutic approaches have been pursued. The three most important treatment methods treat the described defects with moldable miniplates, with special moldable reconstruction plates, and, as already mentioned, with specially manufactured patient-specific plates.

[0009] Miniplates, such as those disclosed in WO 00 / 66012 A1 and WO 03 / 068091 A1, are bone plates with a relatively thin material thickness. They have the advantage that they are already widely used as standard plates for simple and easily reducible fractures and can be used flexibly, especially in the lower jaw. The miniplates can be easily shaped to the bone fragments using simple bending instruments. However, due to their material thickness, miniplates have certain limitations, especially under higher loads. Their use for the indications described above often leads to plate fractures and dislocations postoperatively.

[0010] This is where the advantages of reconstruction plates lie: Reconstruction plates are relatively solid plates, typically made of a hard titanium grade or titanium alloy with a material thickness of 2.0 to 3.5 mm, which are very stable and can absorb high forces. These reconstruction plates are usually designed so that the bending areas lie between the attachment openings, with the openings and bending areas arranged in a string of beads. The bending areas allow the plate to be anatomically adapted to the bone fragments from opening to opening.

[0011] However, despite their specially designed deformation areas, reconstruction plates are difficult to adapt to the specific bone shape, especially in the area of ​​the ascending ramus of the lower jaw. Due to the material thickness and strength, very high forces are required to bend the plates. Due to the high forces required, the bending tools must be very solid, precisely fitting, and with appropriate leverage.

[0012] Furthermore, shaping the plates is very time-consuming and requires a great deal of experience on the part of the user. In particular, the bone plates cannot be shaped directly onto the patient's lower jaw. Because the bone plate must have a certain degree of rigidity for the reasons mentioned above, very large forces would have to be applied, which could further aggravate the existing bone defect. The surgeon must therefore first roughly measure the individual anatomy of the lower jaw and then bend the bone plate more or less by eye outside the patient. This is usually done using one or more bending pliers. Alternatively, so-called templates, i.e. soft metal plates, can be used. These are bent to the jaw like a template, and the bone plate to be bent is then bent outside the patient using this template in the manner described.

[0013] However, such bending using bending pliers is generally not very precise. This is especially true because the bone plate is generally not intended to run in a single plane. It can therefore happen that the bent bone plate is not, or only inadequately, adapted to the lower jaw. In this case, the surgeon must perform several adjustment steps. Due to the inherent brittleness of the material (e.g., grade 4 titanium), this is only possible a few times. There is a risk that the material of the bone plate could be weakened by repeated bending to such an extent that it could break either during the operation or postoperatively in the patient.

[0014] Furthermore, strain hardening and microcracks can occur due to the molding process. Especially with plates for the lower jaw, the widely varying angles between the corpus and the ascending ramus may necessitate significant deformation of the plates in the mandibular angle area. This exacerbates the microcracking described above and often leads to postoperative plate fractures, particularly in areas of severe deformation.

[0015] In addition, due to the array of openings, the bone screw closest to the fracture or defect must bear the greatest load. Due to this high localized load, screw fractures or osteonecrosis often occur postoperatively in the area of ​​the bone screw near the fracture or defect. Especially when bridging bone defects, the sawtooth-like outer contours of the reconstruction plates often lead to soft tissue irritation or even soft tissue necrosis in the bridging area.

[0016] In addition, bending a bone plate, for example as disclosed in WO 01 / 82809, with known bending pliers can also lead to undesired bending within the plate plane or to undesired torsions.

[0017] Patient-specific implants can eliminate the aforementioned disadvantages of miniplates and reconstruction plates, but they are very complex to plan and prepare, requiring a certain number of specialists for their manufacture. In addition, patient-specific implants are currently only useful for planned procedures and are relatively expensive compared to mass-produced plates.

[0018] US 4,726,808 discloses mandibular plates with a central section and two wings extending from it, which can be arranged on opposite sides of a ramus. In a central section, the prosthesis is essentially strip-shaped and contains openings for bone screws arranged along a midline of the central section. However, the arrangement of the wings on opposite sides of a ramus is complex. Furthermore, these plates are difficult to shape to a patient's individual anatomy, particularly in the area of ​​the ascending ramus. In order to be able to provide a suitable bone plate for as many defects as possible without having to accept the risks mentioned above (such as the risk of microcracks due to excessive deformation), a large assortment of different bone plates must always be kept on hand, which is complex and costly.

[0019] Document RU 2 033 105 C1 discloses a bone plate for treating mandibular fractures in the symphysis area. The bone plate shown in the figures has a type of framework structure. However, fixation extending into the ramus area is not possible with this bone plate. Furthermore, this bone plate is also difficult to mold to a patient's individual anatomy, so a large assortment of different bone plates must always be kept on hand.

[0020] WO 2010 / 080511 A1 discloses three-dimensional truss implants (but not generic bone plates) that can, for example, replace part of a lower jaw. However, even these implants cannot be easily adapted to a patient's individual anatomy, so a large assortment of different bone plates must always be kept on hand. Furthermore, these truss implants are not designed to withstand the bending forces occurring within the plate plane, especially in the area of ​​the ascending ramus, which occur, for example, during chewing or swallowing.

[0021] WO 2013 / 096592 A1 also discloses devices and methods for promoting bone growth, which have a trabecular lattice structure intended to promote bone growth. Generic bone plates are therefore not disclosed. Furthermore, these structures also lack easy adaptability to a patient's individual anatomy. Furthermore, these structures are not designed to withstand the bending forces occurring within the plate plane, especially in the area of ​​the ascending ramus, which occur, for example, during chewing or swallowing.

[0022] The document DE 103 35 281 A1 discloses a grid arrangement for osteosynthesis. The Figures 1 to 3The bone plates shown contain double rows of screw holes, each arranged in a straight line and connected by diagonally running webs to form a flat grid arrangement. However, this grid arrangement is also difficult to adapt to a patient's individual anatomy. Furthermore, these grids are not designed to withstand the bending forces that occur within the plate plane, particularly in the area of ​​the ascending ramus, such as those that occur during chewing or swallowing. Furthermore, the outer edges of the ring-shaped receptacles for the bone screws have edges that are uncomfortable for the patient and could even lead to injury to body tissue.

[0023] EP 1 182 972 B1 discloses osteosynthetic bone plates for the treatment of fractures, particularly mandibular fractures. These bone plates are also difficult to mold to a patient's individual anatomy without having a large assortment of different bone plates on hand.

[0024] In view of the disadvantages described above, the object of the present invention is to provide a bone plate which does not have these disadvantages. In particular, the bone plate should be easily moldable to the individual anatomy of a patient without requiring the maintenance of an excessively large assortment of different bone plates or the risk of microcracking or strain hardening due to excessive deformation. Furthermore, the bone plate should preferably provide the required stability in the load-bearing areas close to the fracture and be able to distribute the loads in the anchoring area across several bone screws. Furthermore, the bone plate should preferably be as thin as possible and be provided with a soft-tissue-protecting outer contour in the fracture or bridging area.

[0025] The object of the present invention is to further develop the bone plate known from the prior art in such a way that it allows the top or bottom of the bone plate to be placed selectively against a bone and to accommodate one and the same bone screw in both orientations and to fix its locking element. This object is achieved by a bone plate having the features of claim 1. Advantageous developments of the invention are the subject of the dependent claims. In particular, a surgical set containing at least one bone plate and at least one bone screw is the subject of claim 4.

[0026] The term "embodiment" or "exemplary embodiment" used in this description does not necessarily indicate ways of carrying out the claimed invention, but also includes examples that contribute to an understanding of the invention.

[0027] This task is solved, on the one hand, by a bone plate for the reconstruction or trauma treatment of a bone. In particular, this can be a human bone, such as the human mandible. Alternatively, the bones can also be, for example, the talus, navicular, cuneiform, or metatarsal I in a medial column procedure in the foot.

[0028] The bone plate includes a main section with a first end and a second end, a first contact surface for contact and attachment to a first region of the bone, and a plurality of receptacles, each with at least one opening, particularly a circular opening, for receiving at least one fastening element. The first region of the bone can be, for example, the corpus of the lower jaw. Alternatively, if the bones to be treated are the bones for a "medial column surgery" in the foot, the first region can consist of one or more of the talus, navicular, cuneiform, and metatarsal I bones. The fastening element is preferably a bone screw.

[0029] At least two adjacently arranged wings extend from at least the first end of the main section. The phrase "adjacently arranged" here means that the wings extend within one and the same substantially planar surface or within two substantially planar surfaces whose spacing is smaller than the thickness of the wings, or that the wings are at least deformable such that they extend within one and the same substantially planar surface or within two substantially planar surfaces whose spacing is smaller than the thickness of the wings—particularly in contrast to the wings shown in US Pat. No. 4,726,808, which extend in planes that are significantly further apart.

[0030] The wings extending from the first end of the main section preferably extend at an angle to each other that is less than 90°, preferably less than 60°, and particularly preferably less than 45°. These angle ranges have proven particularly advantageous for the treatment of a human lower jaw.

[0031] The wings each have a second contact surface for contact and attachment to a second region of the bone, as well as at least one receptacle, each with at least one opening, particularly a circular opening, for receiving at least one fastening element. The second region of the bone can, for example, be the ascending ramus of a mandible, in particular an outer side of this ascending ramus. Alternatively, if the bones are the bones for a "medial column surgery" in the foot, the second region can consist of one or more of the talus, navicular, cuneiform, and metatarsal first bones. The receptacles of the wings can also be designed to accommodate at least one bone screw each.

[0032] It is also within the scope of the disclosure that not only at least two adjacent wings extend from the first end of the main section, but also that at least one wing or at least two adjacent wings, which have / have the above-mentioned properties, extend from the second end of the main section. The main section and the at least two wings are designed such that the main section has a first minimum bending stiffness with respect to an axis running perpendicular to the first contact surface, and each of the at least two wings has a respective second minimum bending stiffness with respect to an axis running perpendicular to the second contact surface.If the main section or at least one of the wings is curved, or if the main section runs at an angle to at least one of the wings, the aforementioned perpendicular axes are not necessarily parallel to each other at different points on the contact surface of the main section or the wing. Therefore, here and in the following, local axes are always assumed to be perpendicular to the contact surface.

[0033] According to common technical understanding, flexural rigidity indicates the magnitude of the bending moment relative to the resulting curvature. For a homogeneous material, flexural rigidity is the product of the elastic modulus of the bone plate material (in the area of ​​the main section or one of the wings) and the axial area moment of inertia with respect to a cross-sectional plane passing through the bone plate (i.e., through the main section or one of the wings).

[0034] For the present invention, only those cross-sectional planes are considered that are perpendicular to the respective contact surface, i.e., parallel to an axis that is perpendicular to the contact surface. To calculate the axial area moment of inertia with respect to such a cross-sectional plane, a Cartesian coordinate system is used, the origin of which is formed by the centroid of this cross-sectional area and the x-axis of which is perpendicular to the contact surface and, together with the z-axis, spans the cross-sectional area. The y-axis is thus perpendicular to the cross-sectional area and parallel to the contact surface. The axial area moment of inertia can be calculated using the integral ∫ A z 2 dA the squared z-coordinate over the cross-sectional area A. In this way, the bending stiffness according to the invention is obtained with respect to the x-axis perpendicular to the contact surface: When a bending moment is applied around the bending axis x, which is perpendicular to the contact surface, a curvature occurs around this bending axis x and thus within the contact surface.

[0035] The aforementioned bending stiffness obviously depends on the choice of cross-sectional plane, i.e., with reference to the coordinate system introduced above, in particular on the choice of the y-axis and thus also the z-axis, which together with the x-axis running perpendicular to the contact surface spans this cross-sectional plane. Here and in the following, the first minimum bending stiffness (i.e. the minimum bending stiffness of the main section) with respect to an axis running perpendicular to the first contact surface is regarded as the smallest bending stiffness with respect to a (local) axis running perpendicular to the first contact surface (with reference to the coordinate system introduced above, with respect to the local x-axis), which results from all cross-sectional planes running through the main section and perpendicular to the contact surface. The minimum bending stiffness of the wings is understood in an analogous manner.

[0036] The first minimum bending stiffness (i.e., the minimum bending stiffness of the main section) is greater than each of the second minimum bending stiffnesses (i.e., the minimum bending stiffnesses of the wings), but smaller than the minimum total bending stiffness of all wings extending from the first end. If not only at least two adjacent wings extend from the first end of the main section, but also at least two adjacent wings extend from the second end of the main section, the first minimum bending stiffness (i.e., the minimum bending stiffness of the main section) can also be greater than each of the second minimum bending stiffnesses of the wings extending from the second end of the main section, but smaller than the minimum total bending stiffness of all wings extending from the second end.

[0037] Analogous to the above definition, the second minimum total bending stiffness with respect to an axis perpendicular to the second contact surface is understood as the minimum bending stiffness with respect to a (local) axis perpendicular to the second contact surface, which results from all cross-sectional planes perpendicular to the second contact surface. However, only those cross-sectional planes that pass through all wings extending from the first end are considered. A common coordinate center is assumed for the calculation of the total bending stiffness and the area moment of inertia. The minimum total bending stiffness of the wings is therefore not the same as the sum of the minimum bending stiffnesses of the individual wings; the minimum total bending stiffness is in fact greater than the sum of the minimum bending stiffnesses of the individual wings.

[0038] As already indicated above, the curvature of the bone plate caused by a bending moment is proportional to the applied bending moment and inversely proportional to the bending stiffness. The greatest curvature, and thus the greatest deformation, therefore occurs in the region of the bone plate where the bending stiffness is minimal.

[0039] The relationships explained above lead to the following advantageous bending properties: In the initial state, not yet fixed to the bone, the wings can be bent individually within the plate plane by applying a comparatively small bending moment. Since the first minimum bending stiffness is greater than either of the second minimum bending stiffnesses, the greatest deformation occurs in the area of ​​the wings in this initial state. Thus, the wings can be deformed relatively easily within the plate plane without significantly deforming the main section.

[0040] If the bone plate is fixed to the bone with its main section and wings in the implanted state, the wings are also fixed relative to each other, so that in this implanted state, the minimum total bending stiffness is relevant. Since this is greater than the first minimum bending stiffness, the wings can hardly be deformed within the plate plane in the implanted state. If the bone to be treated is the lower jaw, the requirement that the total bending stiffness be greater than the first bending stiffness is due to the actual force distribution in the lower jaw: Near the joint, the load on the bone during chewing / biting is greater than towards the chin.

[0041] The flexural rigidity of the main section with respect to an axis parallel to the contact surface, which determines the curvature of the main section out of the plate plane (according to the above definition, i.e., when bending around the z-axis), is preferably smaller than the minimum flexural rigidity of the main section with respect to the axis that determines the curvature within the plate plane (according to the above definition, i.e., when bending around the x-axis). The same applies analogously to the wings. This makes it possible to bend the main section or wings out of the plate plane.

[0042] As has been shown, for adaptation to most human mandibles, it is sufficient if, with an appropriate plate design, the main section of the bone plate is only bent out of the plane defined by the contact surface (i.e., by bending around the z-axis, based on the coordinate system above), but not within this plane (i.e., around the x-axis, based on the coordinate system above). Bending within the plane defined by the contact surface would also increase the risk of work hardening.

[0043] Instead, the greatest differences between human mandibles lie in the angle at which the ascending ramus extends relative to the body, the height of the ascending ramus, and the length of the body. The wings provided for this purpose are easily bendable not only out of the plane defined by the contact surface, but also within the plane of the plate—at least as long as they are not yet attached to the mandible.

[0044] To determine whether a given bone plate meets the bending properties explained above, it is not absolutely necessary to know the first minimum bending stiffness of the main section, the second minimum bending stiffness of the wings, and the minimum total bending stiffness of the wings numerically. Rather, it is sufficient to meet the bending properties if that a first lower bound for the bending stiffnesses is known, which is smaller than all bending stiffnesses with respect to local axes running perpendicular to the first contact surface (with reference to the coordinate system introduced above with respect to the local x-axes) resulting from the cross-sectional planes running through the main section and perpendicular to the first contact surface; that each of the wings has a bending stiffness with respect to at least one cross-sectional plane running through this wing and perpendicular to the second contact surface, with respect to a local axis running perpendicular to the second contact surface, which is smaller than said first lower bound;that a second lower limit for the total bending stiffnesses is known, which is smaller than all total bending stiffnesses with respect to local axes running perpendicular to the second contact surface, which result from the cross-sectional planes perpendicular to the second contact surface, whereby only those cross-sectional planes are used for this purpose, which run through all wings extending from the first end; that the main section has a bending stiffness with respect to at least one cross-sectional plane running through the main section and perpendicular to the first contact surface, with respect to a local axis running perpendicular to the first contact surface (with reference to the coordinate system introduced above with respect to the local x-axis), which is smaller than said second lower limit.

[0045] To minimize deformation of the main section within the contact surface, the main section can have a truss structure. This means that the main section has bracings that run transversely to a centerline extending from the first end to the second end of the main section, i.e., perpendicular and / or parallel and / or preferably diagonally to this centerline. Advantageously, the supports form nodes of the truss structure, and the bracings run between these supports. However, truss structures are also conceivable in which only a few or no supports form nodes.

[0046] It is conceivable that at least one, preferably all, wings also contain a truss structure as described above. However, at least one wing, and particularly preferably each wing, preferably does not have such a truss structure. In this way, it can be achieved that, at least in the non-implanted initial state, the wings are more easily deformable than the main section with respect to an axis running perpendicular to the respective contact surface.

[0047] The main section can be delimited on at least one side, preferably on both sides, by at least one frame structure having an outer edge that runs essentially straight. The outer edge is referred to as essentially straight if its minimum radius of curvature is greater than 10 mm at least on the long sides of the main section and / or its width measured perpendicular to the center line does not vary by more than 2 mm over a length of 10 mm along the center line. This makes it possible to avoid edges such as those caused, for example, by the annular screw receptacles of DE 103 35 281 A1, which can be uncomfortable for the patient and could even lead to injury to body tissue. However, in the area of ​​the first end and the second end of the main section and / or on the wings, the radius of curvature can also be smaller, or the width measured perpendicular to the center line can also vary more.

[0048] The main section can have a width in the range from 2 mm to 20 mm, preferably from 5 mm to 15 mm, particularly preferably from 8 mm to 10 mm. The length of the main section measured along a center line can be in the range from 25 mm to 300 mm, preferably from 50 mm to 250 mm. At least one wing, preferably each wing, can have a length in the range from 10 mm to 60 mm, preferably from 20 mm to 40 mm. Furthermore, at least one wing, preferably each wing, can have a width in the range from 2 mm to 10 mm. Furthermore, at least one wing, preferably each wing, can have a width that is at most 80% of the width of the main section. Such dimensions and ratios, which can also be selected independently of one another, are suitable for human lower jaws.

[0049] Perpendicular to the contact surfaces (i.e., the first contact surface and the second contact surfaces), the bone plate can have a thickness ranging from 1 mm to 3 mm, preferably from 1 mm to 2 mm. However, due to the bending properties and / or the lattice structure, such small thicknesses do not result in a loss of flexural rigidity.

[0050] Preferably, the bone plate is substantially flat. This means that both the main portion and the wings extend substantially in a common plane (apart from the extension of the bone plate due to its aforementioned thickness). The above bone plate from US 4,726,808 is not flat according to this definition, as its two wings extend in different planes. A substantially flat bone plate can be manufactured more easily than one that is already adapted to the anatomical shape. In addition, a substantially flat shape simplifies the transport and storage of the bone plate.

[0051] Furthermore, the main section is preferably essentially deformable into an anatomical shape only by bending out of the plane defined by the contact surface, in which shape it can be fastened to at least part of a lower jaw, in particular a human one. In other words, the main section is designed such that it does not need to be bent, or at most only needs to be bent insignificantly, about the axis running perpendicular to the contact surface in order to be converted into the anatomical shape. As explained above, bendability should be reduced so that the bone plate, even in the implanted state, can only be deformed slightly by forces or bending moments acting within the aforementioned planes.

[0052] The bone plate is preferably made of a biocompatible implant material, such as titanium and its alloys, implant steel, implantable plastic or implantable ceramic.

[0053] In many situations, it is advantageous if a bone screw can be fixed at different angles relative to the bone plate by appropriately designing both a locking element of the bone screw, in particular the screw head, and the plate opening. Such structures on screw heads and plate openings are disclosed, for example, in the international patent application WO 2004 / 086990. However, the plate openings disclosed there only allow variable-angle fixation of the locking element, in particular the screw head, if the screw is inserted through the opening from a predetermined upper side of the bone plate towards a predetermined opposite lower side of the bone plate; variable-angle fixation in a direction opposite to this is not possible. This can limit the usability of the bone plates for some applications.

[0054] It is the object of the present invention to further develop the bone plates known from the prior art and in particular their openings in such a way that suitable bone screws (in particular the bone screws disclosed in WO 2004 / 086990) can be fixed to the bone plate at variable angles in both directions.

[0055] This object is achieved by a bone plate with at least one opening for accommodating at least one bone screw. In particular, this can be a bone plate as described above for the reconstruction or trauma treatment of a particularly human bone, such as a particularly human lower jaw.

[0056] The opening penetrates the bone plate along a longitudinal axis from an upper side of the bone plate to an opposite lower side of the bone plate. The opening opens at the upper side into a first receiving area, which is designed to receive and, in particular, fixate a locking element of a bone screw at a variable angle in a first direction.

[0057] According to the invention, the opening on the underside opens into a second receiving area, which is designed to receive and, in particular, fix the locking element at a variable angle in a second direction. The second direction is essentially opposite to the first direction. This is understood here and below to mean that the locking element can be received and fixed in the first receiving area such that the bone screw penetrates the bone plate from the top side toward the underside, and that the locking element can be received and fixed in the second receiving area such that the bone screw penetrates the bone plate from the bottom side toward the top side.

[0058] Preferably, the first receiving area is delimited by a first inner wall, and the second receiving area is delimited by a second inner wall, wherein at least one recess is formed in each of the first inner wall and the second inner wall, and in each of these recesses, the distance of the respective inner wall increases as a function of the circumferential angle around the longitudinal axis. Even more preferably, both the first inner wall and the second inner wall are formed at least approximately spherical, paraboloidal, ellipsoidal, or hyperboloidal in the region of each of the respective recesses.

[0059] In other words, the opening preferably contains an inner wall both in the region of the upper side of the bone plate and in the region of the lower side of the bone plate, wherein these inner walls are each designed as disclosed in WO 2004 / 086990.

[0060] The first and second receiving areas of the opening can be designed independently of one another for clockwise or counterclockwise locking. For example, clockwise locking for the first receiving area means that the locking element of the bone screw can be fixed in the first receiving area by turning the bone screw clockwise, as viewed from the top side of the bone plate to the bottom side of the bone plate. Similarly, counterclockwise locking for example, for the second receiving area, means that the locking element can be fixed in the first receiving area by turning the bone plate counterclockwise, as viewed from the top side of the bone plate to the bottom side of the bone plate.

[0061] Preferably, the first and second receiving areas of the opening are configured for co-rotating locking. This means that either both receiving areas are configured for clockwise locking or both receiving areas are configured for counterclockwise locking.

[0062] This design allows a suitably designed bone screw to be inserted both from the top side toward the bottom side through the opening, thus securing it at a variable angle, and from the bottom side toward the top side through the opening, thus securing it at a variable angle. This makes it possible to design bone plates, particularly the bone plates described above, in such a way that either the bottom side or the top side can be applied to the bone. In particular, one and the same bone plate can be used for either a left-sided or a right-sided defect. This way, even fewer different bone plates are required to allow for individual adaptation, which further simplifies storage.The bone plate even allows some applications in which at least one first bone screw can be inserted through a first opening from the top towards the bottom and at least one second bone screw can be inserted through a second opening from the bottom towards the top of one and the same bone plate and fixed at a variable angle.

[0063] The first and / or the second inner wall may, independently of one another, have one, several or all of the features disclosed in WO 2004 / 086990.

[0064] In particular, the inner wall may have at least three or even exactly three recesses distributed evenly along its circumference, each of which widens wedge-shaped outwards away from the longitudinal axis of the receptacle; and / or the receptacle area may be provided with a countersink, in particular a spherical one, for receiving, for example, a screw head with a spherical head underside.

[0065] The invention further relates to a surgical set comprising at least one bone plate as described above, having at least one opening with two receiving areas, and at least one bone screw with a screw shaft and a locking element, in particular a screw head protruding outward beyond the screw shaft and a thread of the screw shaft. The locking element can be selectively received in the first receiving area or the second receiving area of ​​the opening of the bone plate and, in particular, can be fixed at a variable angle.

[0066] Preferably, the locking element, in particular the screw head, is provided with a circumferential outer surface that extends substantially in the direction of a longitudinal axis of the bone screw and has at least one clamping surface that widens outwardly from the longitudinal axis in a wedge shape, viewed in an azimuth plane perpendicular to the longitudinal axis. Preferably, the circumferential outer surface of the locking element is configured to be at least approximately spherical, paraboloidal, ellipsoidal, or hyperboloidal, at least in the region of the clamping surface.

[0067] In other words, the bone screw is preferably designed as disclosed in WO 2004 / 086990.

[0068] A bone screw configured in this way allows for selective insertion into the opening of the bone plate in essentially opposite directions, as already explained above. The bone screw can also have one, several, or all of the features disclosed in WO 2004 / 086990.

[0069] In particular, the outer surface can have at least three or even exactly three clamping surfaces evenly distributed along its circumference, each of which widens outwards in a wedge shape away from the longitudinal axis.

[0070] Furthermore, a reconstruction set for the reconstruction of a human mandible in particular is described, wherein the reconstruction set comprises at least one bone plate as described above and at least one of the following further elements: at least one connecting plate which has means for connecting to at least one of the bone plates or a part of one of the bone plates, in particular at least one opening for receiving a fastening element, in particular a connecting screw or a bone screw, at least one temporomandibular joint prosthesis and optionally at least one support element for holding the temporomandibular joint prosthesis, wherein the temporomandibular joint prosthesis and / or the support element has means for connecting to at least one wing, preferably all wings extending from the first end of the main section of the bone plate, in particular at least one opening for receiving a fastening element, in particular a connecting screw or a bone screw.

[0071] Such a reconstruction set requires only a comparatively small number of different elements, which nevertheless can treat a large number of defects in the human lower jaw, as described below in connection with the Figures 9a-i and 10 will be explained later.

[0072] Optionally, the reconstruction set may contain further bone plates not according to the invention - for example, bone plates with a main section from the ends of which only one wing or no wing at all extends.

[0073] Said connecting plate can have two openings in at least one end region, which can be simultaneously aligned with at least two corresponding openings in at least one of the bone plates or at least a portion of one of the bone plates. A fastening element designed as a connecting screw can penetrate one of the openings of a bone plate for connection, and an external thread of the connecting screw can penetrate an internal thread in the connecting plate.

[0074] In the following, the invention is explained in detail using several exemplary embodiments. Figure 1: a panoramic X-ray view of a human lower jaw with a first bone plate according to the invention attached thereto; Figure 2: a panoramic X-ray view of a human lower jaw with a second bone plate according to the invention attached thereto; Figure 3a: a panoramic X-ray view of a human lower jaw with a third bone plate according to the invention attached thereto; Figure 3b: a perspective sectional view along the Figure 3adrawn section line III-III; Figure 4a: a perspective view of the second bone plate according to the invention according to Figure 2; Figure 4b: a perspective detailed view of the second bone plate according to the invention; Figure 5a: a top view of the second bone plate according to the invention; Figure 5b: a sectional view of the second bone plate according to the invention along the section line EE shown in Figure 5a; Figure 6a: a perspective view of a first bone screw of a surgical set according to the invention; Figure 6b: a top view of the first bone screw of a surgical set according to the invention; Figure 7: a first reconstruction set with a first bone plate according to the invention, a second bone plate according to the invention, and a connecting plate in two views;Figure 8: a second reconstruction set with three bone plates according to the invention, one bone plate not according to the invention, a connecting plate, a right and a left temporomandibular joint prosthesis, a support element for holding one of the temporomandibular joint prostheses, four connecting screws for connecting the temporomandibular joint prostheses to the support element, four connecting screws for optionally connecting one of the bone plates to the support element or to the connecting plate, and a temporomandibular joint stabilization element; Figures 9a-i: nine panoramic X-ray views of human lower jaws with various defects and elements of the reconstruction set according to Figure 8; Figure 10: a further overview of human lower jaws with various defects and elements of the reconstruction set according to; Figure 8; Figures 11a and b: two views of a second bone screw with a screw head and a locking element arranged at the tip; Figures 12a and b: two views of a third bone screw without a screw head, but with a locking element arranged at the tip; Figures 13a to c: three perspective views of a surgical set according to the invention with a bone plate according to the invention and four bone screws; Figure 14a: a perspective view of a bone plate according to the invention without bone screws; Figure 14b: a perspective view of the bone plate according to the invention according to Figure 14awith four bone screws inserted therein; Figures 15a to c: three detailed views of a further bone plate with an opening with two receiving areas; Figures 16a to c: three detailed views of a further bone plate with an opening with two receiving areas; Figures 17a to c: three detailed views of a further bone plate with an opening with two receiving areas; Figures 18a to c: three detailed views of a further bone plate with an opening with two receiving areas.

[0075] Figure 1shows a human lower jaw 113 with a corpus 142 and two ascending rami 112. For clarity, a projection similar to a dental panoramic x-ray view was chosen, in which the outer surface of the lower jaw 113 was rolled onto the plane of the drawing. A first bone plate 101 according to the invention is applied and fastened to the lower jaw 113. The bone plate 101 contains a main section 109, which has a first end 143 and an opposite second end 148 and extends along a center line M from the first end 143 to the second end 148. The main section 109 further has a first contact surface 141 (not visible here), to which the main section 109 is applied and fastened to the corpus 142 (see Figure 4a). In addition, the main section 109 has a plurality of receptacles 108, 108', each with a circular opening 102, 102' for receiving a bone screw 301 not shown here (see Figures 6a and 6b ).

[0076] Two wings 110 arranged side by side extend from both the first end 143 and the second end 148 of the main section 109. These wings each have a second contact surface 144 (not shown here) (see also Figure 4a) for applying and fastening to an outer side of one of the ascending branches 112. Furthermore, the wings 110 have receptacles 145, each with a circular opening 146 for receiving a bone screw 301 (not shown here) (see Figures 6a and 6b ).

[0077] The main section 109 has a first minimum flexural rigidity in a cross-sectional plane not shown here with respect to an axis running perpendicular to the first contact surface 141 (and thus also perpendicular to the plane of the drawing) (see Figure 3b for a representation of a cross-sectional plane of another bone plate). Each wing 110 has a respective second minimum flexural rigidity in respective cross-sectional planes, also not shown here, with respect to axes running perpendicular to the respective second contact surface 144 (and thus also perpendicular to the plane of the drawing). The first minimum flexural rigidity is greater than each of the second minimum flexural rigidities, but smaller than the minimum total flexural rigidity of all wings 110 extending from the first end 143 and also smaller than the minimum total flexural rigidity of all wings 110 extending from the second end 148.

[0078] The main section 109 has a truss structure. Namely, it has struts 104 that run transversely to the centerline M. The openings 102 are arranged on a first side of the centerline M, and the openings 102' are arranged on a side of the centerline M opposite the first side. The receptacles 108, 108' with the circular openings 102, 102' are arranged at the nodes of the truss structure. Alternatively, however, nodes without screw holes are also conceivable. In the embodiment shown here, the wings 110 do not have such a truss structure.

[0079] The aforementioned bending properties and the framework structure result in the advantages of the bone plate 101 according to the invention, which were already explained in detail above: In the initial state, particularly in the delivery state, the bone plate 101 can be essentially flat, which facilitates production, transport, and storage. In order to shape the bone plate 101 to the individual anatomy of a patient, suitably selected bending moments within the plate plane allow essentially only the wings 110, but not the main section 109, to be bent. As a result, essentially only the wings 110 in the plate plane can be shaped to the individual anatomy of a patient, for example, to the angle between the corpus 142 and the ascending ramus 112.The main section 109 can essentially only be deformed into an anatomical shape by bending it out of the plane defined by the contact surface 141, in which it can be attached to the lower jaw 113.

[0080] As studies have shown, with appropriate shaping of the bone plates, deformation of the main section 109 within the plate plane is not even necessary in order to be able to mold the bone plate 101 to the corpus 142 of a variety of human mandibles 113. Instead, the low deformability of the main section 109 within the plate plane has the advantage that the bone plate 101 is stable against forces and bending moments acting in this plate plane.

[0081] Once the bone plate 101 is attached to the lower jaw 113, the two wings 110 are also fixed relative to each other, so that in this implanted state, the minimum total flexural rigidity of these wings 110 is relevant. Since this total flexural rigidity is greater than the first minimum flexural rigidity of the main section 109, the wings 110 can hardly be deformed within the plate plane in the implanted state, which also leads to greater stability in this area against forces and bending moments acting in the plate plane. If the bone to be treated is a lower jaw, the requirement that the total flexural rigidity be greater than the first flexural rigidity is due to the actual force distribution in the lower jaw: Near the joint, the load on the bone during chewing / biting is greater than towards the chin.

[0082] The main section 109 is bounded on both sides S 1 , S 2 by a frame structure 105, which has an outer edge 107 that runs essentially straight. This avoids edges that could, for example, lead to injuries to body tissue.

[0083] The main section 109 has a width b 1 of 10 mm and a length l 1 of 145 mm measured along the center line M. The wings 110 have a width b 2 of 7 mm. Figure 1 The shorter wings 110 shown above have a length l 2 of 19 mm, and the Figure 1 The longer wings 110 shown below have a length l 2 ' of 26 mm. Thus, each wing 110 has a width b 2 that is at most 80% of the width b 1 of the main section 109.

[0084] The bone plate is made of a biocompatible implant material, such as titanium and its alloys, implant steel, implantable plastic or implantable ceramic.

[0085] The Figures 2 and 3a show a human lower jaw 113 with two further bone plates 101' and 101" according to the invention. Their main sections 109 each have two wings 110 only at a first end 143. At the opposite second end 148, only a single wing 110 is arranged. The main section 109 of the bone plates 101' and 101" according to the invention Figure 3a The third bone plate 101'' according to the invention shown is longer than the main section 109 of the Figure 2 shown second bone plate 101' according to the invention. Thus, the Figure 3a illustrated third bone plate 101 according to the invention can cover a larger area of ​​the corpus 142, as will be explained below in connection with the Figures 9a to 9i and 10 becomes clear.

[0086] In Figure 3b is a cross-sectional view along section line III-III in Figure 3a shown. The cross-sectional plane runs perpendicular to the center line M of the main section 109. However, it is not necessarily the one at which the minimum bending stiffness of the main section 109 is present. A Cartesian coordinate system is shown, the origin of which is formed by the common centroid P of the three partial cross-sectional areas A 1 , A 2 and A 3 . The x-axis is perpendicular to the contact surface 141, and the y-axis runs essentially parallel to the center line M. The x-axis and the z-axis together span the partial cross-sectional areas A 1 , A 2 and A 3 . The axial area moment of inertia can be calculated using the integral ∫ A z 2 dA = ∫ A 1 z 2 dA + ∫ A 2 z 2 dA + ∫ A 3 z 2 dA the squared z-coordinate over the cross-sectional area A composed of the three partial cross-sectional areas A 2 , A 2 , and A 3 . For each of the three integrals, a common coordinate system is used, the coordinate origin of which lies at the center of gravity of the total area and not the center of gravity of the partial cross-sectional areas. The flexural rigidity results from the product of this axial area moment of inertia with the modulus of elasticity of the bone plate 101''. However, as explained above, in order to determine whether the bone plate 101" fulfills the bending properties explained above, it is not absolutely necessary to know the first minimum flexural rigidity of the main section 109, the second minimum flexural rigidities of the wings 110, and the minimum total flexural rigidity of the wings 110 numerically exactly.

[0087] Figure 4a shows a perspective view of the second bone plate 101' according to the invention according to Figure 2 The main section 109 has a first contact surface 141 for contact and attachment to the body 142, and the two wings 110 each contain a second contact surface 144 for contact and attachment to the ascending branch 112.

[0088] Each of the openings 102, 102' and 146 has a structure which is shown in the detailed view according to Figure 4b The opening 102 serves to accommodate a Figures 6a and 6b illustrated first bone screw 301. The opening 102 penetrates the bone plate 101 along a longitudinal axis L from an upper side 202 of the bone plate 101 to an opposite lower side 203 of the bone plate 101. At the upper side 202, the opening 102 opens into a first receiving area 204, which is delimited by a first inner wall 205. At the lower side 203, the opening 102 opens into a second receiving area 206, which is delimited by a second inner wall 207.

[0089] Three recesses 208 are formed in the circumferential direction in the first inner wall 205. In each of these three recesses 208, the distance of the first inner wall 205 increases depending on the angle of revolution around the longitudinal axis L. Furthermore, in the exemplary embodiment shown here, the first inner wall 205 is spherical in the region of each of the recesses 208. Alternatively, the first inner wall 205 can, for example, also be paraboloidal, ellipsoidal, or hyperboloidal. Analogously, three recesses 209 are formed in the circumferential direction in the second inner wall 207. In each of these three recesses 209, the distance of the second inner wall 207 increases depending on the angle of revolution around the longitudinal axis L. Furthermore, in the exemplary embodiment shown here, the second inner wall 207 is spherical in the region of each of the recesses 209, but could alternatively also be paraboloidal, ellipsoidal, or hyperboloidal.The first receiving area 204 also contains a spherical countersink 210 for receiving a connecting element, in particular a screw head, of a bone screw (not shown here). Furthermore, the first recess 204 has a run-out contour 212, which serves to guide a bone screw out.

[0090] The two receiving areas 204, 206 are designed for co-rotating locking. More precisely, both receiving areas 204, 206 are designed for clockwise locking. A locking element of a bone screw can thus be fixed in the first receiving area 204 by turning the bone screw clockwise, as viewed from the top side 202 to the bottom side 203, and in the second receiving area 206 by turning the bone screw clockwise, as viewed from the bottom side 203 to the top side 202.

[0091] Figure 5ashows a top view of the second bone plate 101' according to the invention. As in the sectional view according to Figure 5b As can be seen, the second receiving area 206 also contains a spherical countersink 211 and a run-out contour 213.

[0092] The Figures 6a and 6bshow a first bone screw 301, which can be inserted at a variable angle into each of the openings 102, 102' and 146. This bone screw 301 is identical to the one disclosed in WO 2004 / 086990. It has a screw shaft 320 with a thread 321 and a screw head 310 designed as a locking element, which protrudes outward beyond the screw shaft 320 and the thread 321. The screw head 310 has an engagement contour 311, into which, for example, a screwdriver can be inserted to screw the bone screw 301 in or out. Furthermore, the screw head 310 is provided with a circumferential outer surface, which extends essentially in the direction of a longitudinal axis K of the bone screw 301 and has three clamping surfaces 330 evenly distributed in the circumferential direction. Viewed in an azimuth plane perpendicular to the longitudinal axis K, the clamping surfaces 330 widen wedge-shaped outwards and away from the longitudinal axis K.The outer surface is spherical in the region of the clamping surfaces 330. These clamping surfaces 330 allow the screw head 310 to be selectively locked to the first inner wall 205 or the second inner wall 207, as described in detail in WO 2004 / 086990 (which, however, only discloses an opening with a single receiving area as disclosed here).

[0093] In this way, the bone screw 301 can be inserted either from the top side 202 toward the bottom side 203 through the opening 102 and thus fixed to the bone plate at a variable angle, or from the bottom side 203 toward the top side 202 through the opening 102 and thus fixed to the bone plate at a variable angle. This allows both the top side 202 and the bottom side 203 to serve as contact surfaces for contact with the bone. The bone plates can therefore be used selectively and as needed for left-sided or right-sided defects without having to forego variable-angle fixation. This significantly reduces the range of bone plates that must be kept on hand.

[0094] The Figure 7 The reconstruction set shown contains the two Figures 2 to 3billustrated bone plates 101' and 101" according to the invention and a connecting plate 131, which is shown here twice in two different views. As a means for connecting to a bone plate, for example one of the bone plates described above, the connecting plate 131 contains several openings 132 for receiving a fastening element, such as a Figure 8 The connecting screw 163 shown here can penetrate one of the openings 102, 102', or 146 of the bone plates according to the invention, or even an opening in another bone plate, for connection purposes, and its thread can penetrate into a thread in the connecting plate. This allows for variable extension or even the coupling of two plates to adapt to the individual anatomy or bone defect.

[0095] Figure 8 shows a second reconstruction set. This contains the bone plates 101, 101' and 101" according to the invention Figures 1 to 3b ; a bone plate 101‴ not according to the invention, which has only a single wing 110 at each end of the main section 109; a bone plate as in Figure 7Represented connecting plate 131; one temporomandibular joint prosthesis 160 each for the left and right side; a support element 161 for holding and adjusting the height of one of the temporomandibular joint prostheses 160 and for attaching it to a bone plate or for direct attachment to the bone (alternatively, the reconstruction set can also contain several support elements 161); connecting screws 162 (four in the exemplary embodiment shown here) for connecting one of the temporomandibular joint prostheses 160 to the support element 161; connecting screws 163 (four in the exemplary embodiment shown here) for connecting the support element 161 to one of the wings 110 or for connecting the connecting plate 131 to one of the bone plates; a temporomandibular joint stabilization element 164 for transversely connecting two wings 110 by means of connecting screws 163 (alternatively, the reconstruction set can also contain several temporomandibular joint stabilization elements 164).

[0096] In the Figures 9a to 9i is shown how the reconstruction set according to Figure 8 can be used for a variety of bone defects: According to Figures 9a and 9b Smaller bone defects can be treated using the shorter bone plate 101'. Figure 9c shows how a larger defect can be treated using the longer bone plate 101''. Using a shortened bone plate 101'', the support element 161, a temporomandibular joint prosthesis 160 and a temporomandibular joint stabilization element 164 as well as the associated connecting screws 162 and 163, a temporomandibular joint can also be replaced, as shown in Figure 9d is shown. Figure 9e shows the use of bone plate 101 for a large central defect. In Figure 9f Another use of the bone plate 101' is shown, where the defect is even larger than in the Figures 9a and 9b . In the situation according to Figure 9gTwo bone plates 101' and 101" were used, which were connected using the connecting plate 131. While the bone plate 101' was trimmed in the area of ​​the chin, this was done for the bone plate 101" in the area of ​​the chin and the ascending ramus. In addition, a temporomandibular joint prosthesis 160, the support element 161 and the temporomandibular joint stabilization element 164 with associated connecting screws 162 and 163 were also inserted here. Figure 9h shows again the use of the longer bone plate 101''. In Figure 9i Finally, the use of bone plate 101''' can be seen.

[0097] Alternatively, a reconstruction set is also conceivable, in which a temporomandibular joint prosthesis can be connected directly to one of the bone plates, i.e. without an additional support element. Figure 10 shows again an overview of a variety of bone defects according to the usual HCL classification: L-defects (lateral continuity defects) can be treated with the shorter bone plate 101', which has two wings at only one end. Only defects on the right side of the patient are shown; due to the double receiving areas of the openings described above, the same bone plate 101' can also be used on the left side of the patient. For CL-defects (lateral and central continuity defects), the longer bone plate 102' can be used, which also has two wings at only one end. Only defects on the right side of the patient are shown; due to the bilateral blocking described above, the same bone plate 102' can also be used on the left side of the patient. C-defects (central continuity defects) can be treated with the bone plate 101‴, which in the version shown here does not have two wings at either end.However, plates for C-defects with two wings on one or both sides are conceivable. For the treatment of LCL defects (double lateral and central continuity defects), the bone plate 101 (upper four illustrations) or the bone plates 101' or 101" together with the connecting plate 131 (lower six illustrations) can be used. For H-defects (hemimandibular continuity defects), either a temporomandibular joint prosthesis 160 with support element 161 can be used alone, or the temporomandibular joint stabilization element 164 and one of the bone plates can be used additionally. In the application shown at the very top of column "H," no bone plate is used; instead, the support element 161 is attached directly to the bone. Here, too, only the use on the right side of the patient is shown (see above).For CH defects (hemimandibular and central continuity defects), a combination of bone plate 101'' cut at the wings 110, temporomandibular joint stabilization element 164, support element 161, and temporomandibular joint prosthesis 160 can be used. Here, too, only the use on the right side of the patient is shown (see above).

[0098] Overall, it appears that all bone defects can be treated with a comparatively small reconstruction kit. This is due, among other things, to the reversible usability of the bone plates, which is due to the inventive double-sided openings.

[0099] In the Figures 11a and 11bA second bone screw 340 is shown. This includes a screw head 341 with an engagement contour 342, a screw shaft 343 with a thread 347, and a locking element 345 arranged at an end 344 of the bone screw 340 opposite the screw head 341. This locking element 345 includes three clamping surfaces 346 distributed evenly in the circumferential direction, which are designed as disclosed in WO 2004 / 086990.

[0100] The Figures 12a and 12b show a third bone screw 350, which, however, does not have a screw head. At a first end 351, it has an engagement contour 352, and at a second end 354 opposite the first end 351, it has a locking element 355, which, like the one in the Figures 11a and 11b The locking element 345 shown has three clamping surfaces 356. A screw shaft 353 with a thread 357 extends between the first end 351 and the second end 354.

[0101] The Figures 13a to 13c show the inventive bone plate 101' from Figure 2 with two as in the Figures 11a and 11b Bone screws 340 shown and two as shown in the Figures 6a and 6b Bone screws shown 301.

[0102] In the view according to Figure 13a the shorter bone screws 301 are according to Figures 6a and 6b from the top side 202 of the bone plate 101' towards the bottom side 203 and penetrate the openings 102'. The bone screws 340 according to Figures 11a and 11b are directed with their ends 344 towards the underside 203, but not yet in contact with it. In the position according to Figure 13b the bone screws 340 are inserted and fixed in the openings 102 by means of the locking elements 345. Figure 13c contains a perspective view of the top side 202 of the bone plate 101'.

[0103] If sufficient fixation cannot be achieved with the bone screws 301 alone, the bone screws 340 can provide additional stability. For example, the shorter bone screws 301 can penetrate through the bone plate 101' and then penetrate from the outside into a lower jaw, while the longer bone screws 340 can penetrate the lower jaw completely from the inside to the outside and then engage the bone plate 101'. One possible indication is bone degradation, which may have occurred, for example, due to previous radiation therapy.

[0104] The Figures 14a and 14b show the same bone plate 101', in whose openings 102, 102', however, according to Figure 14bfour of the shorter bone screws 301 can be inserted. A first bone screw 301 and a second bone screw 301 penetrate the bone plate 101' from the top side 202 to the bottom side 203, with the first bone screw 301 penetrating an opening 102 and the second bone screw 301 penetrating an opening 102'. A third bone screw 301 and a fourth bone screw 301 penetrate the bone plate 101' from the bottom side 203 to the top side 202, with the third bone screw 301 penetrating an opening 102 and the fourth bone screw 301 penetrating an opening 102'.

[0105] In one possible application, a first part of the bone plate 101' could be screwed in the area of ​​a temporomandibular joint from the oral cavity, while a second part of the bone plate 101' could be screwed in the corpus region from the outside.

[0106] The Figures 15a to 15c show sections of another bone plate 360, which in Figure 15ain a perspective view, in Figure 15b in a top view and in Figure 15c in a sectional view along the Figure 15b The bone plate 360 ​​contains an opening 361, which opens into a first receiving area 364 on an upper side 362 of the bone plate 360 ​​and opens into a second receiving area 366 on a lower side 363. Both the first receiving area 364 and the second receiving area 366 contain a conical internal thread 367 and 368, respectively, which widen towards the upper side 362 and the lower side 363, respectively. In this exemplary embodiment, both internal threads 367, 368 are identical to one another.

[0107] The Figures 16a to 16c show sections of another bone plate 370, which in Figure 16a in a perspective view, in Figure 16b in a top view and in Figure 16c in a sectional view along the Figure 16bThe bone plate 370 contains an opening 371, which opens into a first receiving area 374 on an upper side 372 of the bone plate 370 and opens into a second receiving area 376 on a lower side 373. Both the first receiving area 374 and the second receiving area 376 contain a conical internal thread 377 and 378, respectively, which widen towards the upper side 372 and the lower side 373, respectively. In this exemplary embodiment, only the opening angles of the two internal threads 377, 378 are identical; however, the first internal thread 377 is higher than the second internal thread 378.

[0108] The Figures 17a to 17c show sections of another bone plate 380, which in Figure 17a in a perspective view, in Figure 17b in a top view and in Figure 17c in a sectional view along the Figure 17bThe bone plate 380 contains an opening 381, which opens into a first receiving area 384 on an upper side 382 of the bone plate 380 and opens into a second receiving area 386 on an underside 383. Both the first receiving area 384 and the second receiving area 386 are circular-cylindrical in shape, but do not contain internal threads. Between the two receiving areas 384, 386 there is an intermediate area 389, which is also circular-cylindrical in shape, but whose radius is smaller than that of the receiving areas 384, 386.

[0109] The Figures 18a to 18c show sections of another bone plate 390, which in Figure 18a in a perspective view, in Figure 18b in a top view and in Figure 18c in a sectional view along the Figure 18bThe bone plate 390 contains an opening 391, which opens into a first receiving area 394 on an upper side 392 of the bone plate 390 and opens into a second receiving area 396 on a lower side 393. Both the first receiving area 394 and the second receiving area 396 are conical and widen towards the upper side 392 and the lower side 393, respectively. Between the two receiving areas 394, 396 there is a circular-cylindrical intermediate area 399, the radius of which is smaller than the smallest radius of the receiving areas 394, 396.

[0110] In the openings 361, 371, 381, 391 of the Figures 15a to 18c Bone screws with a slotted screw head (such as in CH 669 105 A5) or with a spherical screw head (such as in CH 675 531 A5) can be used for the bone plates 360, 370, 380, 390 shown.

Claims

1. Bone plate (101; 101'; 101''; 360; 370; 380; 390), containing at least one opening (102, 102', 146; 361; 371; 381; 391) for receiving at least one respective bone screw (301; 340; 350), wherein the opening (102, 102', 146; 361; 371; 381; 391) extends through the bone plate (101; 101'; 101''; 360; 370; 380; 390) along a longitudinal axis (L) from an upper side (202; 362; 372; 382; 392) to an opposite lower side (203; 363; 373; 383; 393), wherein the opening (102, 102', 146; 361; 371; 381; 391) at the upper side (202; 362; 372; 382; 392) opens into a first receiving region (204; 364; 374; 384; 394), which is designed to receive and fix a locking element (310; 345; 355) of a bone screw (301; 340; 350) in a first direction, characterized in that the opening (102, 102', 146; 361; 371; 381; 391) on the underside (203; 363; 373; 383; 393) opens into a second receiving region (206; 366; 376; 386; 396), which is designed to receive and fix the locking element (310; 345; 355) in a second direction, the second direction being essentially opposite to the first direction.

2. Bone plate (101; 101'; 101'') according to claim 1, wherein the first receiving region (204) is bounded by a first inner wall (205), the second receiving region (206) is bounded by a second inner wall (207), wherein at least one recess (208, 209) is formed in each of the first inner wall (205) and the second inner wall (207), wherein in each of these recesses (208, 209) the distance of the respective inner wall (205, 207) increases as a function of the angle of rotation about the longitudinal axis (L).

3. Bone plate (101; 101'; 101'') according to claim 2, wherein both the first inner wall (205) and the second inner wall (207) are at least approximately spherical, paraboloidal, ellipsoidal or hyperboloidal in the region of each of the respective recesses (208, 209).

4. Bone plate (101; 101'; 101'') according to one of the preceding claims, wherein the first receiving region (204; 364; 374; 384; 394) is designed for variable-angle fixation of the blocking element (310; 345; 355) in the first direction and the second receiving region (206; 366; 376; 386; 396) is designed for variable-angle fixation of the blocking element (310; 345; 355) in the second direction.

5. Surgical set, comprising at least one bone plate (101; 101'; 101''; 360; 370; 380; 390) according to one of the preceding claims and at least one bone screw (301; 340; 350) with a screw shank (320; 343; 353) and a locking element (310; 345; 355), in particular a screw head (310) projecting outwards beyond the screw shank (320) and a thread (321) of the screw shank (320; 343; 353), wherein the locking element (310; 345; 355) can be received selectively in the first receiving region (204; 364; 374; 384; 394) or in the second receiving region (206; 366; 376; 386; 396) of the opening (102, 102', 146; 361; 371; 381; 391) and in particular can be fixed at variable angles.

6. Surgical set according to claim 5, wherein the locking element (310; 345; 355) is provided with a circumferential outer surface which extends substantially in the direction of a longitudinal axis (K) of the bone screw (301; 340; 350) and has at least one clamping surface (330; 346; 356) which - viewed in an azimuthal plane perpendicular to the longitudinal axis (K) - widens outwards away from the longitudinal axis (K) in a wedge shape.

7. Surgical kit according to claim 6, wherein the circumferential outer surface of the blocking element (310; 345; 355) is at least approximately spherical, paraboloidal, ellipsoidal or hyperboloidal at least in the region of the clamping surface (330; 346; 356).