Hip joints may suffer degeneration through disease or through wear. Hip joint endoprostheses have proven useful for therapy. These comprise a femoral component, which is implanted at the upper end of the thigh bone, and a hip component, which interacts with the femoral component and is implanted in the pelvic bone (acetabulum). In many cases, it can happen that the pelvic bone is damaged in the region of the hip joint. This has the effect of making it difficult to fasten the hip joint component to the pelvic bone. This is especially true of implants that function as a partial replacement of the pelvis. These have additional fastening elements in order not only to achieve secure anchoring of the joint socket of the hip joint implant on the pelvic bone, but also to stabilize the pelvic bone itself.
Some hip joint implants of this kind are known, they have a plurality of fastening elements on a support body that comprises the actual joint socket. These fastening elements comprise elongate brackets which extend in a cranial direction and which are provided with a plurality of drilled holes to permit fastening by means of a bone screw. Moreover, opposite these fastening brackets, a caudally directed and shorter bracket is provided, which can optionally also be configured like a hook. They serve to securely fasten and stabilize the implant, and in particular the joint socket thereof, on a damaged pelvic bone.
A tried and tested material for implants is TiAl6V4 which, although sufficiently robust, nevertheless has the disadvantage that it cannot be reshaped during surgery. Pure titanium, by contrast, is much easier to reshape, but, due to a lack of dimensional stability, it is not routinely used for the pelvic socket component. This conflict of objectives has not hitherto been able to be satisfactorily resolved.
The object of the disclosure is to create an improved hip joint implant that avoids these disadvantages and others. The disclosure moreover extends to a corresponding production method.
In accordance with one or more embodiments, devices and methods are provided.
In a hip joint implant for fastening to a pelvic bone, with a support body which has a socket and whose convex outer face is designed to bear on the pelvic bone and which, on its concave inner face, has a receiving seat for a pelvis-side bearing component that is designed to receive a joint head of a femoral component of a hip prosthesis, and with outwardly directed flat fastening brackets which are arranged at the edge region of the socket and are each provided with at least one receiving seat for a fastening means,
In some embodiments of the present disclosure, for a disclosed hip joint implant, provision is made according to the disclosure that the fastening brackets are made of a reshapeable (cold-formable) substantially biocompatible material and are connected to the socket via a cohesive bond, wherein the socket is made of another, stiffer substantially biocompatible material.
As used herein, the term “reshapeable” is understood to mean a material that is substantially plastically deformable at room temperature, such that fastening brackets formed from this material can be manually adapted, with or without hand tools, to an underlying structure. This disclosure also refers to these abilities of a material as “cold-form able”.
In contrast to “reshapeable” or “cold-formable”, “non-cold-formable” material identifies material that cannot be plastically deformed manually, or by using hand tools, at room temperature.
As used herein, the term “biocompatible” or “biocompatible material” refers to any material which upon implantation into a mammal's body that does not elicit a substantial detrimental response in vivo, and/or a material exhibiting essentially no cytotoxicity or immunogenicity while in contact with body fluids, tissues and/or bones. For example, the biocompatible material can be selected from the group consisting of titanium (of any grade), Nitinol®, steel, surgical steel, calcium, copper, zinc, iron, cobalt, magnesium, manganese, vanadium, molybdenum, silicate, strontium, tungsten, chromium, nickel, aluminum, and ceramics, composites, alloys (such as TiAl6V4), compounds, and mixtures thereof.
The bearing component can be designed as an insert which is made of a material that promotes sliding and which functions as a receiving seat and sliding partner for a joint head. Such an insert is usually fastened by being cemented or clamped in the support body, but other types of fastening can also be provided. The bearing component can also be designed, however, as an interposition component. This is usually understood to mean an intermediate piece of this type that changes an opening angle of the socket, in particular for adaptation to particular anatomical conditions. The element forming the sliding partner for the joint head is then received in this intermediate piece. Moreover, the bearing component can also be introduced into and fixed in the support body as a dual mobility insert.
The disclosure includes the concept of a division of material, in the sense that different materials are used for the fastening brackets and the socket-like support body, and these materials can be cohesively connected, and therefore can be permanently connected, to one another. The fastening brackets are produced from a reshapeable, biocompatible material, for example titanium (for example of grade 2, grade 3 or grade 4, however, any suitable grade can solely be used, or be included in combination with other grades and/or other materials). This material can possibly, at least partially, be reshaped intraoperatively by the surgeon, so that the support body that is ultimately implanted can achieve a relatively good adaptation to the respective individual peculiarities of the pelvic bone of the respective patient.
By contrast, for the support body with the socket, which by means of a bearing component forms the bearing for the joint head of the femoral component, another biocompatible material is used, for example a titanium alloy such as TiAl6V4. This material is stiffer as compared to the fastening bracket material, cost-effective, mechanically robust and only marginally reshapeable. However, the latter is not wholly necessary for the socket; on the contrary, the lack of reshapeability increases the robustness and dimensional accuracy of the socket, even under relatively high loads. By virtue of the dimensional accuracy, the construction according to the disclosure is particularly suitable for sockets of modular design, with alternative sockets and socket inserts being used if necessary.
The disclosure has recognized that the hitherto unresolved conflict between a robust and cost-effective implant, on the one hand, and good reshapeability for better adaptation and fastening to the individual shape of the pelvic bone, on the other hand, can be resolved.
The cohesive bonds of the present disclosure can be a welded connection, in particular as an electron beam welded connection. This affords the advantage of a high degree of reproducibility and a good welding result with relatively minimal heat input. As a result of the relatively low heat input, there is also only a small amount of distortion. Furthermore, it permits the welding of various materials to each other, for example titanium with titanium alloys. This connection also permits a high degree of automation, which likewise benefits the reproducibility and therefore the quality of the connection as a whole.
The cohesive bond is advantageously designed with a welded-through weld seam. A square butt weld, which permits reliable fastening and safe through-welding with little heat input, can be used. However, the cohesive bond can be formed through any other welding process and/or any adhesive material addition.
The fastening brackets can be configured individually and separately from the fastening ring. However, in the context of the present disclosure, the fastening brackets are designed and described as being in one piece with a fastening ring, which engages around the socket-like support body and is connected to the socket by means of the cohesive bond. This provides for good pre-assembly, namely of the fastening brackets to the fastening ring. After this has been prefabricated (and, if necessary, reworked), it can be pre-assembled with the socket-like support body.
The fastening brackets can be prefabricated with openings for fastening means. In some embodiments, these will be drilled or formed holes that are configured to receive fastening screws (such as bone screws) for fastening the bracket to the pelvic bone. Furthermore, the fastening ring can be prefabricated to the extent that it has an opening which is dimensioned in such a way that it functions to receive the socket-like support body. The opening is preferably prefabricated to a dimension that corresponds to an external dimension of the support body, in particular to an external diameter of the socket of the support body. Advantageously, the opening in the fastening ring can be configured with a corresponding dimension in such a way that it forms an interference fit with the socket-like support body. This permits an initial fixing, which can be a step of pre-assembly.
The socket itself can be made of a non-cold-formable material, for example any material that is less deformable than the socket-like support body, such as titanium (of any grade), Nitinol®, steel, surgical steel, calcium, copper, zinc, iron, cobalt, magnesium, manganese, vanadium, molybdenum, silicate, strontium, tungsten, chromium, nickel, aluminum, and ceramics, composites, alloys (such as TiAl6V4), compounds, and mixtures thereof. As one example, an alloy of TiAl6V4 that achieves a tensile strength of 800 MPa or greater can be used, with titanium itself achieving a tensile strength of ca. 300 MPa.
The socket-like support body can be provided with a support shoulder and/or a centering ring in the region where the fastening ring is received. The support shoulder can be designed entirely or partially circumferentially. The support shoulder can thus form a stop for the fastening ring, such that the position of the latter is defined when the fastening ring is pushed onto the socket. The centering ring can aid in positioning the fastening ring in a substantially central position. The centering ring can also serve as an interface for a modular system. This makes it possible to use other types of sockets too, for example sockets that belong to a modular system consisting of several components. These can also include sockets that are designed differently but have a uniform external diameter. This is especially true when several uniform external diameters are provided, which are graduated in different external diameter sizes.
The transition region between the socket and fastening brackets or fastening ring can be provided with a milled surface. This can be applied, for example, as part of secondary processing after the cohesive bonding. On the one hand, this makes the fastening ring smaller and, on the other hand, the surface quality is improved.
The disclosure further relates to a method for producing, and a method of implanting, a corresponding hip joint implant.
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the disclosure, and, together with the summary given above, and the detailed description of the embodiments below, serve as a further explanation and disclosure to explain and/or illustrate embodiments of the disclosure.
It is noted that the drawings of the present application are provided for illustrative purposes only and, as such, the drawings are not drawn to scale. It is also noted that like and corresponding elements are referred to by like reference numerals.
In the following description, numerous specific details are set forth, such as particular structures, components, materials, dimensions, processing steps and techniques, in order to provide an understanding of the various embodiments of the present application. However, it will be appreciated by one of ordinary skill in the art that various embodiments of the present application may be practiced without these specific details. In other instances, well-known structures or processing steps have not been described in detail in order to avoid obscuring the present application.
As used herein, the term “substantially” or “substantial”, is equally applicable when used in a negative connotation to refer to the complete or near complete lack of an action, characteristic, property, state, structure, item, or result. For example, a surface that is “substantially” flat would either be completely at, or so nearly flat that the effect would be the same as if it were completely flat.
As used herein, terms defined in the singular are intended to include those terms defined in the plural and vice versa.
As used in this specification and its appended claims, terms such as “a”, “an” and “the” are not intended to refer to only a singular entity, but include the general class of which a specific example may be used for illustration, unless the context dictates otherwise. The terminology herein is used to describe specific embodiments of the disclosure, but their usage does not delimit the disclosure, except as outlined in the claims.
Unless otherwise indicated, all numbers expressing quantities of ingredients, properties such as molecular weights, reaction conditions, and so forth as used in the specification and claims are to be understood as being modified in all instances by the term “about.” Accordingly, unless indicated to the contrary, the numerical parameters in the specification and claims are approximations that may vary depending upon the desired properties sought to be obtained by the present disclosure. At the very least, and without limiting the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques. Notwithstanding that the numerical ranges and parameters describing the broad scope of the disclosure are approximations, the numerical values in the specific examples are reported as precisely as possible. Any numerical value, however, inherently contains standard deviations that necessarily result from the errors found in the numerical value's testing measurements.
Thus, reference herein to any numerical range expressly includes each numerical value (including fractional numbers and whole numbers) encompassed by that range. To illustrate, reference herein to a range of “at least 50” or “at least about 50” includes whole numbers of 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, etc., and fractional numbers 50.1, 50.2 50.3, 50.4, 50.5, 50.6, 50.7, 50.8, 50.9, etc. In a further illustration, reference herein to a range of “less than 50” or “less than about 50” includes whole numbers 49, 48, 47, 46, 45, 44, 43, 42, 41, 40, etc., and fractional numbers 49.9, 49.8, 49.7, 49.6, 49.5, 49.4, 49.3, 49.2, 49.1, 49.0, etc. In yet another illustration, reference herein to a range of from “5 to 10” includes whole numbers of 5, 6, 7, 8, 9, and 10, and fractional numbers 5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5.7, 5.8, 5.9, etc.
In the discussion and claims herein, the tern “about” indicates that the value listed may be somewhat altered, as long as the alteration does not result in nonconformance of the process or structure to the illustrated embodiment. For example, for some elements the term “about” can refer to a variation of ±0.1%, for other elements, the term “about” can refer to a variation of ±1% or ±10%, or any point therein.
Reference now will be made in detail to embodiments of the disclosure. It will be apparent to those skilled in the art that various modifications and variations can be made in the present disclosure without departing from the scope or spirit of the disclosure. For instance, features illustrated or described as part of one embodiment can be used on another embodiment to yield a still further embodiment.
An illustrative embodiment of a hip joint implant according to an embodiment of the disclosure is shown in
In this embodiment, the hip joint implant is designated as a whole by reference number 1 and comprises a socket-like support body 6 on which two flat and elongate fastening brackets 2 are arranged pointing upward (cranially). A shorter fastening bracket 3, extending downward (caudally), is provided on the opposite side of the socket-like support body 6 (in the following also called socket for short).
In another embodiment described in this application, the location and/or use of a hip joint implant 100 can be the same as the hip joint implant 1's location in
In the illustrative embodiment shown, the implant 1 is composed of two components, a socket 6 and a fastening component, which comprises the fastening brackets 2, 3 and a fastening ring 4, on which the fastening brackets 2, 3 are arranged. In other embodiments the implant 1 can include a socket 106, which is further discussed below.
In
Reference is now made to
In
In
Fastening brackets 102 and 103 are arranged protruding radially outward on a ring 104, which is designated as a fastening ring 104. In this embodiment shown, fastening brackets 102, and 103 and the fastening ring 104 are one piece, however, in other embodiments the fastening brackets 102, 103 and the fastening ring 4 are two or more pieces joined together in any suitable way.
In
The fastening brackets 102, 103 and the fastening ring 104 can be made of a biocompatible material, which is relatively easily deformed manually. Alternatively, or in addition to the biocompatible material, the fastening brackets 102, 103 and the fastening ring 104 can be made of any suitable material that can substantially maintain a shape upon deformation, such as metal(s) (such as titanium aluminum, magnesium, etc. and combinations thereof), plastic(s), epoxy(s), rubber(s), cellulose based material(s), organic material(s) such as leather(s), fabric(s)(woven and/or non-woven), carbon based material(s), and combinations thereof.
Thus, it is therefore possible for the operator to relatively easily, and comparatively easier than reshaping of the fastening brackets 2, 3 and the fastening ring 4, at least partially reshape the fastening brackets 102, 103 and the fastening ring 104 prior to or even during the implantation, i.e. during the operation, if necessary. This relative ease of reshaping the fastening brackets 102, 103 and the fastening ring 104 is due to one or more of (1) the higher workability and ease of reshaping of the material of the fastening brackets 102, 103 and the fastening ring 104, and/or (2) inclusion of narrow portions 124 in each of the fastening brackets 102, 103 and the fastening ring 104. As can be seen in
This reshaping of the fastening brackets 102, 103 and the fastening ring 104 can both (1) better adapt the fastening brackets 102, 103 and the fastening ring 104 to the particular anatomical features of the pelvic bone 9 of the respective patient, and (2) provide a model shape so that once the fastening brackets 102, 103 and the fastening ring 104 are removed from contacting the patient's pelvic bone 9, the fastening brackets 102, 103 and the fastening ring 104 can provide a model for reshaping of a to be implanted fastening brackets 2, 3 and fastening ring 4.
The socket 6 (or socket-like support body 6) is shown in
The socket 6 also includes an outer circumferential face 61, and an optional edge 60. In an inserted configuration (as shown in
The socket-like support body 6 can be made of a biocompatible material that is of sufficient strength so as to take up the bearing forces of the hip joint. TiAl6V4 is one option of biocompatible material the socket-like support body 6 can be formed of.
The socket 106, which can also be referred to as socket-like support body 106, or socket support body 106, is shown in
As the socket-like support body 106 is not configured for implantation, the socket-like support body 106 can be formed of any suitable biocompatible or non-biocompatible material, such as any metal(s), plastic(s), epoxy(s), rubber(s), cellulose based material(s), organic material(s) such as leather(s), fabric(s)(woven and/or non-woven), carbon based material(s), and combinations thereof.
The socket-like support body 106 is configured for relative ease of removal from either inner region 40 or inner region 140 as compared to the socket-like support body 6. This relative ease is based on the structure of the socket-like support body 106, such as distal edge 160A, a tab 170 and a proximal edge 160B on the tab 170. The tab 170 is separated from the other portions of the circumference of the socket-like support body 106 by two tab slots 168.
The distal edge 160A extends substantially orthogonally from circumferential face 161, with the distal edge 160A extending a portion of the circumference of the socket-like support body 106. The circumferential face 161 is configured to contact an inner circumferential face of the fastening ring 4 or an inner circumferential face of fastening ring 104. The distal edge 160A is configured to contact an upper surface of the fastening ring 4 or an upper surface of fastening ring 104.
The proximal edge 160B extends substantially orthogonally from circumferential face 161, with the proximal edge 160B extending at least a portion of the circumference width of the tab 170. The proximal edge 160B is configured to contact an upper surface of the fastening ring 4 or an upper surface of fastening ring 104.
Thus, in an inserted configuration (as shown in
Another view of the socket-like support body 106 is shown in
As the material of fastening brackets 2, and 3, and the material of fastening ring 4 is a reshapeable material,
As the material of fastening brackets 102, and 103, and the material of fastening ring 104 is a reshapeable material,
The fastening brackets 102, and 103, and the fastening ring 104 are comparatively easier to reshape than the fastening brackets 2, and 3, and the fastening ring 4 due to one or more of (1) the higher workability and ease of reshaping of the material of the fastening brackets 102, 103 and the fastening ring 104, and/or (2) inclusion of narrow portions 124 in each of the fastening brackets 102, 103 and the fastening ring 104. Thus, it is comparatively easier for a user to reshape the fastening brackets 102, and 103, and the fastening ring 104 into a configuration as shown in
The advantage of using fastening brackets 102, and 103, and the fastening ring 104 as a guide for fastening brackets 2, and 3, and the fastening ring 4 (which will be implanted) is that manual reshaping of fastening brackets 2, and 3, and the fastening ring 4 can occur away from the patient who is to receive the implant's pelvic bone 9.
The described embodiments and examples of the present disclosure are intended to be illustrative rather than restrictive, and are not intended to represent every embodiment or example of the present disclosure. While the fundamental novel features of the disclosure as applied to various specific embodiments thereof have been shown, described and pointed out, it will also be understood that various omissions, substitutions and changes in the form and details of the devices illustrated and in their operation, may be made by those skilled in the art without departing from the spirit of the disclosure. For example, it is expressly intended that all combinations of those elements and/or method steps which perform substantially the same function in substantially the same way to achieve the same results are within the scope of the disclosure. Moreover, it should be recognized that structures and/or elements and/or method steps shown and/or described in connection with any disclosed form or embodiment of the disclosure may be incorporated in any other disclosed or described or suggested form or embodiment as a general matter of design choice. Further, various modifications and variations can be made without departing from the spirit or scope of the disclosure as set forth in the following claims both literally and in equivalents recognized in law.
Number | Date | Country | |
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63381950 | Nov 2022 | US |