Patent Application
20230030410
The invention relates to an implant for the treatment of bone with the features of the generic term of the independent claim. It is known that bone fractures, especially of the human skull, can be treated with implants. The aim of the treatment and implantation of an implant is generally to restore and maintain the anatomically correct shape and position of the bones to be treated and their surroundings. This promotes the healing process and preserves the functionality of the affected body part after healing has taken place.
In the prior art, various implants are known that are adapted to specific parts of the body.
EP 2 030 596 discloses an implant for the treatment of fractures of the orbit. These include a planar fitting area and a frame structure.
U.S. Pat. No. 5,139,497 discloses an orbital floor implant having a frame structure and a grid.
US 2007/0238069 discloses cuttable and deformable meshes for the treatment of facial fractures.
However, known implants have various disadvantages. For example, certain implants are equipped with frame structures that are adapted to specific bone areas. However, this sometimes makes implant placement difficult, especially since the exact anatomy of people naturally varies. At the same time, however, a certain degree of adaptation to the anatomy is desirable.
It is therefore the task of the present invention to avoid the disadvantages of the prior art, in particular to provide an implant which on the one hand is adapted to the anatomy of the body part to be treated but at the same time allows certain adaptations.
According to the invention, these and other tasks are solved with an implant according to the independent claim.
The implant according to the invention is particularly suitable for covering defects or drill holes or for reconstructing bone defects or malformations. It comprises at least one frame structure and a sheetlike adaptation area. The frame structure is arranged outside the adaptation area. It partially forms the edge of the implant. The frame structure does not, however, completely define the outer edge. This means that at least one area of the outer edge is not limited by the frame structure. This allows the frame structure of the implant to be adapted to a desired anatomy. At the same time, the adaptation area not limited by the frame structure allows cutting or deformation and thus further adaptation to the anatomy.
A frame structure is to be understood as a region of the implant, in particular an edge region, which is designed by means of di-mensioning and/or by material selection and/or shaping in such a way that a minimum force required for plastic deformation of the edge region, in particular preferably the edge region and the adaptation area together, is higher than a minimum force required for plastic deformation of the adaptation area. This property is referred to here and in the following as bendability. A smaller bendability of a part therefore means that a larger force must be applied to plastically deform it. A greater bendability of a part means that a smaller force is sufficient to deform it plastically. Accordingly, the frame structure may be less bendable compared to the adaptation area. Additionally or alternatively, a frame structure can also be a region of the implant, in particular an edge region, which interrupts the periodicity of the lattice.
The implant according to the invention is particularly suitable for the treatment of the human frontal sinus and is shaped and dimensioned accordingly. However, it can of course also be used for other parts of the body if the size and shape are suitable. Particularly preferably, the implant is mirror-symmetrical along a mirror plane.
Preferably, the implant comprises at least two frame structures. These are both arranged outside the adaptation area and thus partially form the edge of the implant. The two frame structures do not continuously delimit the outer edge of the implant. As a result, at least two areas of the outer edge are not bounded by the frame structure. In particular, this allows adaptation to bones that have two similar and/or symmetrical regions, with the intermediate region varying from person to person. For example, the two frame structures may be adapted to the areas around the eyes and have an adaptation area to adapt to the nasal bone.
Preferably, the adaptation area is continuous and is free of frame structures on the inside.
Preferably, the frame structure is dimensioned and arranged such that at least half of the outer edge is not bounded by the frame structure. In the present case, half of the outer edge means half of the length of the outermost edge of the implant.
Preferably, the adaptation area comprises a grid structure. The grid structure is dimensioned in such a way that it can be deformed by hand or with hand tools. In particular, the adaptation area can be designed so that its bendability is adapted appropriately.
In particular, to this end, the adaptation area may be made of or comprise a material having an strain at failure of at least 5%, preferably at least 10%, more preferably at least 15%.
Likewise, the adaptation area can be at least partially dimensioned so that at most a force of 300 N, preferably at most 150 N, particularly preferably at most 50 N, is required to achieve plastic deformation of the adaptation area, in particular a force acting vertically on the adaptation area. For example, the adaptation area can have wire- or rod-shaped elements with a area moment of inertia or material properties to achieve such deformabilities. Depending on the material properties, the dimensions or area moments of inertia of the rod-shaped elements can be different in order to achieve the same deflection for the same force. Similarly, it is conceivable to make the thickness of the adaptation area such that a maximum force, in particular a maximum force listed above, is sufficient to achieve plastic deformation. In particular, the adaptation area can be at most 2 mm, preferably at most 1 mm, especially preferably at most 0.6 mm thick. Particularly preferably, the adaptation area has a thickness of 0.25 mm, 0.4 mm or 0.6 mm. Preferably, the implant comprises a biocompatible material, in particular from the group of implant steel and/or other metals, ceramics and plastics. Particularly preferably, the implant comprises titanium or a titanium alloy.
Preferably, the adaptation area has connection areas that are dimensioned so that they can be cut through using hand tools. This allows a surgeon to easily cut the adaptation area to fit the patient's anatomy.
In particular, the connection areas can be designed as described above in relation to the adaptation area.
The adaptation area preferably comprises a structure of holes whose circumferential areas are connected to each other via convection areas. In particular, the connection areas can be designed as ribs that connect the peripheral areas of the holes at regular intervals along their circumference.
Preferably, the implant has a side length in a range of 10-200 mm. Alternatively, the side length may be in a range of 30-70 mm, or 25-50 mm. In particular, the implant may have an approximately square shape with rounded corner regions. Particularly preferably, the frame structure is arranged in two adjacent rounded corner regions.
Preferably, at least one frame structure is dimensioned and positioned such that it can be attached, in particular screwed, to the margo supraorbitalis.
To this end, the frame structure may have at least one, preferably two, regions that correspond substantially in shape, curvature and/or size to the margo supraorbitalis. For example, the frame structure may have a radius in this region that has a deviation of at most +/−30%, preferably at most +/−20%, particularly preferably at most +/−10% to the radius of the orbit. It is also possible for this region of the frame structure to have a radius that substantially corresponds to the radius of the orbit (i.e. has an approximately equal radius). Particularly preferably, the radius of this region is substantially the same as the radius of the orbit. Further, these regions may have a length that is at most equal to the diameter of the human orbit. For example, the length may be at most 80 mm, preferably at most 60 mm, particularly preferably at most 50 mm.
Preferably, the frame structure has an arc shape. In particular, the arc shape may have a radius of curvature of 10-200 mm, more preferably 10-80 mm. The radius of curvature may vary along regions of the frame structure. For example, the radius of curvature may increase continuously along an edge structure so that the frame structure forms the shape of a clothoid.
Particularly preferably, the implant has an intermediate region. This is arranged between the two frame structures adapted to the margo orbitalis and can have a greater bendability than the two frame structures.
Likewise, it is conceivable that the intermediate region thereby has in particular a length which essentially corresponds to the inner distance between two eye sockets of the human skull and/or the width of a human nose and/or the typical anatomical distance between the human lacrimal glands. Preferably, the connecting piece has a length of 0.5 to 4 cm, particularly preferably of 1 to 2 cm.
Preferably, the implant has at least one attachment tab. Alternatively, the implant can also have at least two attachment tabs. In particular, the attachment tab may be located at the edge of the implant or on a frame structure. Preferably, the attachment tab also has screw holes. This allows the implant to be fixed in a particularly advantageous manner, for example to be screwed to a bone. Preferably, the fixing tab extends away from the edge of the implant in the same plane as the implant, in particular at an azimuth angle between 70° and 95° with respect to the edge. In particular, if the edge of the implant is not straight at the point where a fastening tab is located, the azimuth angle specification should be understood as the angle between the fastening tab and a tangent to the edge of the implant at the point where the fastening tab is located. Particularly preferably, two attachment tabs extend away from the implant such that there is an acute angle between the attachment tabs that opens away from the implant.
Additionally or alternatively, one or more attachment tabs may also be arranged so that they do not lie in the same plane as the implant, as the edge of the implant, or as the adaptation area of the implant and therefore lie at an elevation angle to said plane. In particular, the attachment tab may be angled away from the plane in which at least the edge of the implant and/or a frame structure lies.
It is understood that implants are also conceivable which are not flat but have a free form. In particular, the implant can have local bends between planar elements, and/or have a shape of a rotational or translational surface. In this case, the aforementioned plane refers to a tangent surface to the surface of the implant at the location where the tab is attached. In particular, for tabs that are not in the same plane as the tangent surface, an elevation angle can therefore be measured between the tab and its projection on the tangent surface. An azimuth angle can be measured in the tangent plane between the tab and a tangent to the edge of the implant.
In particular, the at least one attachment tab may be integrally connected to the frame structure. The implant can also have at least two attachment tabs that are integrally connected to the frame structure. If the implant also has at least two frame structures, the at least two attachment tabs are preferably integrally connected to one frame structure each. However, it is also possible for more than one attachment tab to be integrally connected to the same frame structure.
Alternatively, however, it is also possible to arrange one or more attachment tabs at the edge of the implant without connecting them to the frame structure. In particular, one or two attachment tabs can be arranged between two frame structures. This is particularly advantageous if at least one frame structure is dimensioned and positioned in such a way that it can be attacked, in particular fastened with screws, to the margo supra-orbitalis.
Preferably, the at least one attachment tab is adapted for attachment to the nasal bone. The adaptation can be achieved in particular by the dimension, shape, and positioning on the implant. If the implant has at least two attachment tabs, preferably at least two attachment tabs are also adapted in the same way for attachment to the nasal bone.
In particular, the attachment tabs may have a length substantially equal to the length of the human nasal bone. For example, the attachment tabs can have a length of at most 3 cm, preferably at most 2 cm, particularly preferably at most 1.5 cm. Two attachment tabs may be arranged relative to each other such that their smallest distance corresponds to the width of the nasal bone. For example, the distance can be about 5-30 mm. Preferably, the attachment tabs are not arranged parallel to each other in this case. However, it is possible for the attachment tabs to be arranged in a plane at an angle greater than or less than 0°. Attachment tabs that are interlaced about their longitudinal axis are also conceivable.
If an implant has one or two areas adapted for attachment to the margo supraorbitalis, the attachment tabs can in particular be arranged at these areas. Preferably, one attachment tab is arranged on each of the areas adapted for attachment to the margo supraorbitalis. Particularly preferably, the attachment tabs arranged at the regions adapted for attachment to the margo supra-orbitalis, face each other. In this case, the implant may in particular be mirror symmetrical along a plane and/or axis substantially between the two attachment tabs and/or regions adapted for attachment to the margo supraorbitalis. However, non-mirror symmetrical designs are also conceivable.
Preferably, the adaptation area is formed in integrally.
Preferably, the entire implant is formed integrally.
Preferably, the implant is adapted to cover defects or burr holes or to reconstruct bone defects or malformations on the sinus.
Preferably, the adaptation area is plastically deformable. In particular, the adaptation area can be dimensioned or adapted in the choice of material so that plastic deformation is possible.
The invention is explained in more detail below with reference to the figures and embodiments, showing:
Alternatively, it would of course be conceivable to also cut the implant within the frame structure. The frame structure therefore does not have to be designed in such a way that it cannot be cut to size. In general, however, it is advantageous to arrange the frame structure in such a way that it does not have to be cut to size in the most common applications. In this way, the frame structure forms an area without sharp edges.
| Number | Date | Country | Kind |
|---|---|---|---|
| 19216226.1 | Dec 2019 | EP | regional |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2020/085153 | 12/9/2020 | WO |
