HK40104223A - Fixation assembly for securing medical implant in patient - Google Patents

Description

Fixation components used to secure medical implants in a patient's body.

Cross-references to related applications

This application claims the benefit of U.S. Provisional Patent Application 63/126,256, filed December 16, 2020, which is incorporated herein by reference as if fully set forth herein.

Technical Field

This invention relates to medical implants, and more particularly to anchoring systems for medical implants.

Background Technology

As described in U.S. Patent Publication No. 2018/0289493, owned by the applicant (Fumei Corporation, the entire contents of which are incorporated herein by reference, as fully set forth herein), medical implants including hollow anchors having a cavity-like recess or receiving region having raised or surrounding sidewalls, edges, ridges, or lips for attaching cartilage-like flexible material to bone. Another known type of implant is described in PCT application PCT/US2020/063539, also owned by the applicant (Fumei Corporation), and is also incorporated herein by reference, as fully set forth herein.

Difficulties were encountered in anchoring medical implants to the bone. Therefore, there is a desire to provide a more efficient and reliable method for securing implants to patients.

Summary of the Invention

This document discloses a device configured for use as a medical implant, the device including a fixation element. The device includes an anchor body having a first end defining a cavity and an elastic joint member held within the cavity. A second end of the anchor body includes a fixation element extending cantileveredly from the anchor body.

The second end of the anchor body may define a recess, and a fixing element may be secured within this recess. The fixing element includes a threaded portion configured to hold the implant together with the patient recipient site. In one aspect, the first width (W1) of the cavity is greater than the second width (W2) of the recess.

The fixing element may be formed separately from the anchor body, and the fixing element may further include a head portion sized to be retained within a socket. The head portion may include a drive interface configured for tool engagement. The anchor body may be configured to be impacted in a downward direction to secure the anchor body to the head portion, and the head portion may abut against the base of the anchor body in the installed state. In one aspect, the fixing element is integrally formed with the anchor body.

The anchor body may include a socket with a first tapered profile, which is a female Morse taper, while the fixing element may include a head portion with a second tapered profile, which is a male Morse taper. The female Morse taper of the socket and the male Morse taper of the head portion are configured to secure the anchor body to the fixing element together by cold welding or bonding.

An interface region (IR) may be defined between the first tapered profile and the second tapered profile, and this interface region (IR) may be shorter than the axial length ( _LS ) of the threaded portion of the fixing element. The interface region (IR) may be at least 50% of the axial depth of the socket.

The anchor body may further include a sidewall that partially defines the cavity and a collar that defines the insertion port, wherein the sidewall and the collar each have an outer surface layer having a porosity configured to promote intraosseous growth.

The anchor body may define a base that partially defines a cavity on a first surface and an attachment surface for securing the element on a second opposing surface.

The anchor body may define a base that partially defines a cavity on a first surface and an adjacent surface for securing a head portion of the element on a second opposing surface.

In another aspect, a device configured as a medical implant is disclosed, comprising an anchor body having a first end and at least one attachment element. The first end has a sidewall partially defining a cavity, and the at least one attachment element is configured to retain a resilient joint component. A second end of the anchor body includes a collar defining a socket having a first tapered profile, the socket being configured to receive a portion of a fixation element. The device also includes a fixation element comprising a head portion and a threaded portion. The head portion has a second tapered profile and is configured to be inserted into and retained within the socket via an engagement between the first and second tapered profiles. The threaded portion is configured to hold the device together with a patient recipient site.

The anchor body may include a base that partially defines a cavity on a first surface and a second opposing surface that directly faces the head portion of the anchoring element. The base may include at least one attachment element configured to retain a resilient joint member. A first width (W1) of the cavity may be greater than a second width (W2) of the socket. Both the sidewalls and the collar may include an outer layer having a porosity configured to promote intraosseous growth.

In another aspect, a device configured for use as a medical implant is also disclosed. The device includes an anchor body having a first end and at least one attachment element. The first end has a sidewall partially defining a cavity, and the at least one attachment element is configured to retain an elastic joint component. A second end of the anchor body includes a collar integrally formed with the sidewall and defining a socket having a first tapered profile, the socket being configured to receive a portion of a fixation element. The fixation element may include a head portion and a threaded portion. The head portion has a second tapered profile and is configured to be inserted into and retained within the socket via an engagement between the first and second tapered profiles. The threaded portion is configured to hold the device together with a patient recipient site.

The sidewalls and collars can have a constant outer diameter, and both include an outer layer with a porosity configured to promote growth within the bone.

The anchor body includes a base that partially defines a cavity on a first surface and a second opposing surface that directly faces the head portion of the anchoring element.

This document describes additional aspects and embodiments.

Attached Figure Description

The above overview and the following detailed description will be better understood when read in conjunction with the accompanying drawings, which illustrate preferred embodiments of the invention. In the drawings:

Figure 1A shows a perspective view of the implant according to one aspect.

Figure 1B shows another perspective view of the implant in Figure 1A.

Figure 1C shows a fixation element configured for use with the implants of Figures 1A and 1B.

Figure 2A shows a side view of the fixation element and implant before they are attached to each other.

Figure 2B shows another side view of the fixation element and implant before they are attached to each other.

Figure 3 is a cross-sectional view of the fixation element and implant in the joined or attached state.

Figure 4A is a side view of another aspect of the implant, including the integrally formed threaded portion.

Figure 4B is a perspective view of the implant in Figure 4A.

Figure 5 is a cross-sectional view of another embodiment of the implant.

Detailed Implementation

The description provided herein is intended to enable those skilled in the art to make and use the illustrated embodiments. However, various modifications, equivalents, variations, combinations, and alternatives will be apparent to those skilled in the art. Any and all such modifications, variations, equivalents, combinations, and alternatives are intended to fall within the spirit and scope of the invention as defined by the claims.

The use of certain terms in the following description is for convenience only and not for limitation. The terms “left,” “right,” “top,” and “bottom” indicate directions referenced in the accompanying drawings. Unless otherwise specifically stated, the terms “a” and “an” as used in the relevant parts of the claims and specification are defined as including one or more of the referenced items. This term includes the words specifically mentioned above, their derivatives, and words with similar meanings. The phrase “at least one” followed by a series of two or more items, such as “A, B, or C,” refers to any single one of A, B, or C, and any combination thereof.

As shown in Figures 1A and 1B, this document discloses an implant 10 configured for placement within a patient's bone. In one aspect, implant 10 is configured to be implanted into a patient's femur, and more specifically, onto the end of the femur at its junction with the tibia. Those skilled in the art will recognize that implant 10 can be used on any other bone. Further details of implant 10 are disclosed in PCT application PCT/US2020/063539, which is incorporated herein by reference as if fully set forth herein. As shown in Figures 1A and 1B, implant 10 generally includes an anchor body 20 and a resilient joint member 30. Anchor body 20 may include a first end 20a defining a cavity 21, within which the resilient joint member 30 is held. A second end 20b of anchor body 20, opposite the first end 20a, may include fixation elements, such as fixation elements 50, 150, and 250. In one aspect, the fixing elements 50, 150, and 250 may extend cantileveredly from the anchor body 20. Within the anchor body 20, at least one attachment element may be provided to secure the resilient joint member 30 to the anchor body 20. Specifically, in one aspect, a first attachment element 27 may be disposed along the base 22 of the anchor body 20, and a separate second attachment element 28 may be disposed around an edge on a first end 20a of the anchor body 20. In one aspect, the attachment elements 27 and 28 may include a grid structure. Those skilled in the art will understand that various arrangements for the attachment elements or other securing elements can be provided.

The resilient joint component 30 may be formed of a hydrogel and may comprise a polymer molecular matrix configured to cohesively retain water molecules. The resilient joint component 30 is constructed to provide a degree of deformability, such that it returns to a specific non-deformable shape after the application of a load or stress is removed. More specifically, the joint component 30 is formed of a hydrogel consisting of a three-dimensional matrix having a molecular structure made of a complex polymer. In one aspect, the resilient joint component 30 is hydrophilic. Specifically, the resilient joint component 30 includes a relatively high proportion of oxygen atoms (i.e., in hydroxyl groups), nitrogen atoms, or other non-carbon atoms to provide water-absorbing "polar" groups.

The sidewall 25 of the anchor body can be formed as a multi-layered sidewall and includes an outer layer 25a and an inner layer 25b, wherein the outer layer is substantially or generally porous to promote intraosseous growth, and the inner layer is non-porous and configured to provide a barrier for the resilient joint component 30. Those skilled in the art will understand that once the implant 10 is placed within the recipient site of a patient, various structures or contours can be provided on the outer surface or outer layer of the sidewall 25 to promote intraosseous growth.

The anchor body 20 of the implant 10 may include an elongated base portion or collar 34 defining a socket 36. In one aspect, the socket 36 has a completely smooth inner surface. In one aspect, the collar 34 may be defined separately from the sidewall 25, or in another aspect, the collar may be integrally defined with the sidewall 25. As shown in FIG3, the outer surface or outer layer 34a of the collar 34 may be substantially or generally porous to facilitate intraosseous growth, while the inner layer 34b of the collar may be non-porous and solid. In one aspect, the sidewall 25 and the outer layer or outer surface of the collar 34 may have the same porosity or texture and may be configured to facilitate intraosseous growth. In one aspect, the sidewall 25 and the collar 34 are integrally formed with each other and generally have the same features, shape, profile, and composition.

The collar 34 may be formed as a sleeve extending downward or axially away from the base 22 of the anchor body 20, partially defining a cavity 21 for retaining the resilient joint member 30. The collar 34 may include an annular wall portion surrounding the insertion port 36. The collar 34 may be integrally formed with the remainder of the anchor body 20. In one aspect, the radially outer surface of the collar 34 has the same outer diameter as the anchor body 20, such that a continuous radially outer surface is defined by the implant 10.

In one aspect, the axial height of the collar 34 is between 75% and 150% of the axial height of the sidewall 25. The axial height of the collar 34 corresponds to the depth (D) of the socket 36 and is specifically designed to provide sufficient contact surface with the fixing element 50, as described in more detail herein. As shown in FIG1B, the bottom edge 38 of the collar 34 may include a chamfered portion or chamfered profile. The bottom edge 38 may also include a porous outer surface configured to promote intraosseous growth.

In one aspect, the socket 36 defined by the collar 34 may have a tapered profile (TP1), which will be described in more detail below. In one aspect, the socket 36 defines a female moiré tapered profile.

Figure 1C illustrates a fastening element 50. In one aspect, the fastening element 50 is a screw comprising a threaded portion 52 and a head portion 54. Besides helical threads, the fastening element 50 may include other types of fastening or fixing structures. In one aspect, the threaded portion 52 may include a tapered profile. In another aspect, the threaded portion 52 may have a substantially constant profile or outer diameter between the head portion 54 and the end portion 62.

The distal end 62 is configured to engage with the patient's anatomy and hold the fixation element 50 in place relative to the patient. For example, the distal end 62 may be configured to engage with the patient's bone. In one aspect, the radially outer surface of the head portion 54 is smooth and rounded and may be formed as an annular wall. According to one embodiment, the head portion 54 includes a radially outer surface having a tapered profile (TP2). The tapering may begin from a larger diameter region adjacent to the head portion 54 and a smaller diameter region adjacent to the distal end 62. In one aspect, the head portion 54 defines a positive moss tapered profile. In one aspect, the tapering angle for each of the tapered profiles (TP2, TP1) is 1.3 to 1.6 degrees. In one aspect, the tapering angle for each of the tapered profiles (TP2, TP1) is 1.49 degrees (+/- manufacturing tolerance). Those skilled in the art will understand that other types of machine taperings besides moss taperings may be used.

The head portion 54 of the retaining element 50 is configured to engage with the insertion of the collar 34, such that the retaining element 50 engages with and is securely attached to the anchor body 20. The head portion 54 may include a distal portion 56 and a proximal portion 60, the distal portion defining a drive interface 58 configured for tool engagement, and the proximal portion positioned adjacent to the threaded portion 52. In one aspect, as shown in FIG3, the proximal portion 60 has a curved outer surface profile that provides a transition region for connecting the head portion 54 to the threaded portion 52. The distal portion 56 may also include a curved or inclined outer surface profile extending between the head portion 54 and the drive interface 58. In the assembled state, the distal portion 56 of the retaining element 50 is adjacent to or abuts the base 22 of the anchor body 20.

Figure 3 shows the interface region (IR), which illustrates the overlap between the tapered profiles (TP1, TP2) of the anchor body 20 and the fixing element 50. As shown in Figure 3, in one aspect, the interface region (IR) is shorter than the axial length (LS) of the threaded portion 52. In another aspect, the interface region (IR) is less than 20% of the total axial length (LS) of the threaded portion 52. In another aspect, the interface region (IR) is at least 50% of the axial depth (D) of the socket 36. As shown in Figure 3, the width (W1) of the cavity 21 may be greater than the width (W2) of the socket 36. Those skilled in the art will recognize that the widths (W1, W2) can vary.

In one aspect, welding, such as cold welding, is provided between the fixation element 50 and the anchor body 20. In other words, no heating, molding, fusion, adhesive, glue, or other attachment elements or procedures are required to connect the fixation element 50 to the anchor body 20, except for directly impacting the anchor body 20 onto the head portion 54. This provides convenience for surgeons, who can perform the attachment process manually before or during surgery and attach the components with minimal effort, without the need for additional fastening elements (such as adhesives). Due to the interface between the head portion 54 and the socket 36, the attachment between the fixation element 50 and the anchor body 20 can occur independently and directly. Figures 2A and 2B illustrate the fixation element 50 and the implant 10 before attachment or insertion.

In one aspect, the base 22 of the anchor body 20 partially defines a cavity 21 on a first surface 22a and defines an abutting surface for securing the head portion 54 of the element 50 on a second opposing surface 22b. In another aspect, the head portion 54 stops not abutting the second surface 22b of the base 22, but rather the second surface 22b faces directly toward the head portion 54.

In one respect, multiple fixation elements 50 of different sizes and dimensions can be provided for a single implant. This allows surgeons to conveniently select a specific fixation element with a specific depth and thickness of the threaded portion best suited to a particular patient.

During implantation, the fixation element 50 is secured to the patient's recipient site by rotating it. The implant 10 is then impacted or pressed against the head portion 54 of the fixation element 50 to form a moss cone cold metal bond between the two components. Alternatively, the fixation element 50 can be first attached or fastened to the implant 10, and then the combination of the implant 10 and the fixation element 50 can be rotated to engage with the patient's anatomy.

In another aspect shown in Figures 4A and 4B, a separately formed fixation element is not required; instead, the fixation element 150, including the threaded portion 152, can be formed directly and integrally with the anchor body 120. Similar to implant 10, implant 110 also includes a first end 120a of the anchor body 120, which defines a cavity 121 having a base 122' for retaining the resilient joint component 130 via engagement with attachment elements 127, 128. The base portion 134 can extend downward from the sidewall 125. The outer surfaces or outer layers of the base portion 134 and the sidewall 125 can include porous structures configured to promote intraosseous growth. As shown in Figures 4A and 4B, the threaded portion 152 extends directly from the bottom end 123 of the base portion 134. In this embodiment, the entire implant 110 can be rotated such that the threaded portion 152 is screwed into the recipient site. All other aspects of implant 110 are similar to implant 10 unless otherwise specified herein.

Figure 5 illustrates another aspect, in which the fixation element 250 is integrally formed with the anchor body 220. As shown in Figure 5, the threaded portion 252 can be directly formed with the base 222 of the implant 210. The implant 210 similarly includes an elastic joint member 230, sidewalls 225, attachment elements 227, 228, etc., within the cavity 221. The sidewalls 225 may include a porous outer layer 225a and a non-porous inner layer 225b. The elastic joint member 230 extends upward from the first end 220a of the anchor body 220. The fixation element 250, including the threaded portion 252, extends away from the base 222 of the implant 210. This embodiment functions in the same manner as described with respect to the implant 110.

The surgeon can rotate or otherwise engage the implant 210 such that the threaded portion 252 engages with the patient's anatomy. In one aspect, the base 222 partially defines a cavity 221 on a first side surface 222a, and the base 222 defines an attachment surface for fixing the element 250 on a second opposite side surface 222b.

After a detailed description of the present preferred embodiments, those skilled in the art should understand and appreciate that various physical modifications can be made without altering the innovative concepts and principles embodied therein, some of which are illustrated only by way of example in the detailed description. It should also be understood that numerous embodiments are possible that incorporate only portions of the preferred embodiments, without altering the innovative concepts and principles embodied therein, relative to those portions.

Therefore, this embodiment and optional configuration are to be regarded as exemplary and/or illustrative in all respects, and not restrictive. The scope of the invention is defined by the appended claims, rather than by the foregoing description. Thus, all alternative embodiments and variations thereof within the equivalent meaning and scope of the claims are to be included herein.

Claims (20)

1. A device configured for use as a medical implant, the device comprising: An anchor body, the anchor body including a first end defining a cavity and an elastic joint component held within the cavity, and a second end including a fixing element extending cantileveredly from the anchor body. 2. The device of claim 1, wherein a second end of the anchor body defines a socket, the fixing element is fixed within the socket, and the fixing element includes a threaded portion configured to hold the implant together with the patient recipient site. 3. The device according to claim 2, wherein the first width (W1) of the cavity is greater than the second width (W2) of the socket. 4. The apparatus of claim 2, wherein the fixing element is formed separately from the anchor body, and the fixing element further includes a head portion sized to be retained within the socket, and the head portion includes a drive interface configured for tool engagement. 5. The apparatus of claim 4, wherein the anchor body is configured to be impacted in a downward direction to secure the anchor body to the head portion, and the head portion abuts against the base of the anchor body in the installed state. 6. The apparatus according to claim 1, wherein the fixing element is integrally formed with the anchor body. 7. The apparatus of claim 1, wherein the anchor body includes a socket having a first tapered profile, the first tapered profile being a female moss cone, and the fixing element includes a head portion having a second tapered profile, the second tapered profile being a male moss cone, and the female moss cone of the socket and the male moss cone of the head portion are configured to fix the anchor body to the fixing element together by cold welding or bonding. 8. The apparatus of claim 7, wherein an interface region (IR) is defined between the first tapered profile and the second tapered profile, and the interface region (IR) is shorter than the axial length (LS) of the threaded portion of the fixing element. 9. The apparatus of claim 8, wherein the interface region (IR) is at least 50% of the axial depth of the socket. 10. The apparatus of claim 1, wherein the anchor body further comprises a sidewall partially defining the cavity and a collar defining the insertion port, wherein the sidewall and the collar each have an outer surface layer having porosity configured to promote intraosseous growth. 11. The apparatus of claim 1, wherein the anchor body defines a base that partially defines the cavity on a first surface and defines an attachment surface for the fixing element on a second opposing surface. 12. The apparatus of claim 1, wherein the anchor body defines a base that partially defines the cavity on a first surface and defines an adjacent surface for the head portion of the fixing element on a second opposing surface. 13. A device configured for use as a medical implant, the device comprising: Anchor body, the anchor body comprising: A first end and at least one attachment element, the first end having a sidewall partially defining a cavity, the at least one attachment element being configured to retain a resilient joint component, and The second end includes a collar defining a socket having a first tapered profile, the socket being configured to receive part of a fixing element; and A fixation element comprising a head portion and a threaded portion, wherein the head portion has a second tapered profile and is configured to be inserted into and retained within the socket via an engagement between a first tapered profile and a second tapered profile, and the threaded portion is configured to hold the device together with a patient recipient site. 14. The apparatus of claim 13, wherein the anchor body includes a base that partially defines the cavity on a first surface and the base defines a second opposing surface directly facing the head portion of the fixing element. 15. The device of claim 13, wherein the base includes at least one attachment element configured to retain the resilient joint member. 16. The device according to claim 13, wherein the first width (W1) of the cavity is greater than the second width (W2) of the socket. 17. The device of claim 13, wherein both the sidewall and the collar include an outer layer having a porosity configured to promote intraosseous growth. 18. A device configured for use as a medical implant, the device comprising: Anchor body, the anchor body comprising: A first end and at least one attachment element, the first end having a sidewall partially defining a cavity, the at least one attachment element being configured to retain a resilient joint component, and The second end includes a collar integrally formed with the sidewall and defining a socket having a first tapered profile, the socket being configured to receive part of a fixing element; and A fixation element comprising a head portion and a threaded portion, wherein the head portion has a second tapered profile and is configured to be inserted into and retained within the socket via an engagement between a first tapered profile and a second tapered profile, and the threaded portion is configured to hold the device together with a patient recipient site. 19. The device of claim 18, wherein the sidewall and the collar have a constant outer diameter, and both include an outer layer having a porosity configured to promote intraosseous growth. 20. The apparatus of claim 18, wherein the anchor body includes a base that partially defines the cavity on a first surface and the base defines a second opposing surface directly facing the head portion of the fixing element.