TOE IMPLANT, RELATED KIT, SURGICAL METHOD, AND METHOD OF MANUFACTURING
20220346965 · 2022-11-03
Assignee
Inventors
- Herbert E. Schwartz (Fort Wayne, IN, US)
- Matthew L. MROCZKOWSKI (Fort Wayne, IN, US)
- Stone MIGUEL (Fort Wayne, IN, US)
Cpc classification
A61F2002/3092
HUMAN NECESSITIES
A61F2002/30622
HUMAN NECESSITIES
A61F2002/4631
HUMAN NECESSITIES
A61F2/4657
HUMAN NECESSITIES
A61F2002/4233
HUMAN NECESSITIES
A61B90/11
HUMAN NECESSITIES
A61F2/4606
HUMAN NECESSITIES
A61F2002/4681
HUMAN NECESSITIES
International classification
Abstract
Disclosed herein is a toe implant for replacing a portion of a human toe joint, as well as a related kit, surgical method, and method of manufacturing. Specifically, the toe implant may include a bearing member having a curved interface surface and a fixation member coupled to the bearing member. The fixation member may include a first portion having a non-porous barrier, and a tapered second portion.
Claims
1. A toe implant, comprising: a bearing member, comprising: a curved interface surface; and a fixation member coupled to the bearing member, the fixation member comprising: a first portion, comprising: a non-porous barrier; and a tapered second portion.
2. The toe implant of claim 1, wherein the first portion is cylindrical and further comprises: an outer surface having a diameter that is within a range of about 6 mm to about 14 mm.
3. The toe implant of claim 1, wherein the bearing member further comprises: a hydrophilic polymer, comprising: hyaluronic acid; and ultrahigh molecular weight polyethylene.
4. The toe implant of claim 3, wherein the hydrophilic polymer includes self-lubricating properties.
5. The toe implant of claim 1, wherein the curved interface includes at least one of a concave surface and a convex surface.
6. The toe implant of claim 1, wherein the first portion further comprises: a first porous section positioned between the bearing member and the non-porous barrier, the first section comprising: a titanium-based porous material; and a second section positioned between the first section and a third section, the second section comprising: the non-porous barrier; and the third section positioned between the non-porous barrier and the tapered second portion, the third section comprising: the titanium-based porous material.
7. The toe implant of claim 6, wherein the tapered second portion includes the titanium-based porous material; and wherein the titanium-based porous material of at least one of the third section and the tapered second portion includes at least one void capable of receiving bone ingrowth after implantation.
8. The toe implant of claim 1, wherein the tapered second portion comprises an angular outer surface capable of preventing subsidence of the toe implant into a patient's bone.
9. The toe implant of claim 1, wherein the fixation member includes a cross-sectional outer surface shape of at least one of a circle, polygon, triangle, square, rectangle, pentagon, hexagon, heptagon, or octagon.
10. A kit, comprising: a toe implant of claim 1; a guide comprising: a trial toe implant; a shaft; and an engagement slot traversing the trial toe implant and the shaft; a positioning device configured to engage the engagement slot of the guide; a reamer comprising: at least one cutting flute; and a reamer engagement slot configured to engage the positioning device; and a tamper.
11. A surgical method, comprising: exposing a patient's metatarsophalangeal joint; sizing at least one of the patient's metatarsal distal head or phalangeal proximal head; positioning a guide; fixating a positioning device into the at least one of the patient's metatarsal distal head or phalangeal proximal head via the guide's engagement slot; removing the guide; positioning a reamer over the positioning device via the reamer's engagement slot; reaming the at least one of the patient's metatarsal distal head or phalangeal proximal head to a predetermined depth; tamping a toe implant of claim 1 into the at least one of the patient's resected metatarsal distal head or phalangeal proximal head; and closing the patient's incision.
12. A method of manufacturing, comprising: forming a fixation member; and molding, via a compression process, a polymer onto a top portion of the fixation member.
13. The method of claim 12, wherein forming the fixation member further comprises: layering a plurality of sheets of titanium-based material; wherein at least one sheet of the plurality of sheets includes porous material; wherein the porous material comprises a top portion of the fixation member and a bottom portion of the fixation member; wherein at least one sheet of the plurality of sheets includes non-porous material; wherein the non-porous material bisects the top portion of the fixation member from the bottom portion of the fixation member; cutting at least one outer diameter of the fixation member from the plurality of sheets; and cutting an angular outer surface into a bottom segment of the bottom portion of the fixation member.
14. The method of claim 12, wherein molding further comprises: applying heat to the polymer for a time period; and applying pressure to the polymer for the time period; wherein the molding enables the polymer to flow in a controlled manner into voids disposed in the porous material of the top portion of the fixation member; wherein the polymer stops flowing upon reaching the non-porous material.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The subject matter which is regarded as the disclosure is particularly pointed out and distinctly claimed in the concluding portion of the specification. The disclosure, however, may best be understood by reference to the following detailed description of various embodiments and the accompanying drawings in which:
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DETAILED DESCRIPTION
[0033] Generally stated, disclosed herein is a toe implant for replacing a portion of a human toe joint, as well as a related kit, surgical method, and method of manufacturing.
[0034] In this detailed description and the following claims, the words proximal, distal, anterior or plantar, posterior or dorsal, medial, lateral, superior and inferior are defined by their standard usage for indicating a particular part or portion of a patient's body, a bone, a device, or an implant according to the relative disposition of the patient or directional terms of reference. For example, “proximal” means a particular part or portion of a patient's extremity, a bone, a device or implant nearest the torso, while “distal” indicates the portion of the patient's extremity, bone, device or implant farthest from the torso. As for directional terms, “anterior” is a direction towards the front side of the body, bone, device, or implant, “posterior” means a direction towards the back side of the body, bone, device, or implant, “medial” means towards the midline of the body, “lateral” is a direction towards the sides or away from the midline of the body, “superior” means a direction above and “inferior” means a direction below another object or structure. Further, specifically in regard to the foot, the term “dorsal” refers to the top of the foot and the term “plantar” refers the bottom of the foot.
[0035] Similarly, positions or directions may be used herein with reference to anatomical structures or surfaces. For example, as the current devices, instrumentation and methods are described herein with reference to use with the bones of the foot, the bones of the foot may be used to describe the surfaces, positions, directions or orientations of the toe implant, a kit for implant installation, and a surgical method. Further, the devices and methods, and the aspects, components, features and the like thereof, disclosed herein are described with respect to one side of the body for brevity purposes. However, as the human body is relatively symmetrical or mirrored about a line of symmetry (midline), it is hereby expressly contemplated that the device and surgical method, and the aspects, components, features and the like thereof, described and/or illustrated herein may be changed, varied, modified, reconfigured or otherwise altered for use or association with another side of the body for a same or similar purpose without departing from the spirit and scope of the disclosure. For example, the devices, instrumentation and methods, and the aspects, components, features and the like thereof, described herein with respect to a left toe may be mirrored so that they likewise function with a right toe and vice versa. Further, the devices, kit, instrumentation and methods, and aspects, components, features and the like thereof, disclosed herein are described with respect to a toe for brevity purposes, but it should be understood that the devices, systems, instrumentation and methods may be used with other bones and joints of the body having similar structures.
[0036] The first metatarsophalangeal joint (MTP) is a complex joint of the foot where bones, tendons, and ligaments work together to transmit and distribute the body's weight, especially during movement. Cartilage may act as a pad and/or spacer between the first metatarsal and the proximal phalanx to facilitate movement between the bones by reducing friction and preventing the bones from grinding against each other. The present disclosure provides a solution for medical professionals to treat patients with damaged articular cartilage at the MTP joint. In particular, disclosed herein is a toe implant intended to replicate normal anatomy of a patient's metatarsal distal or phalangeal proximal head by recreating the original articular surface geometry. For instance, the bearing member of the implant may be, for example, generally convex to simulate the geometry of the metatarsal distal head or, alternatively, generally concave to simulate geometry of the phalangeal distal head. Further, the toe implant described herein may serve as a replacement pad and/or spacer by recreating the MTP joint space and replicating function of the articular cartilage.
[0037] Referring now to the drawings, wherein like reference numerals are used to indicate like or analogous components throughout the several views, and with particular reference to
[0038] Referring now to
[0039] For an embodiment where the curved interface surface 112 is configured or sized and shaped to replicate the surface of the patient's phalangeal proximal head, the curved interface surface 112 of the bearing member 110 may be configured or sized and shaped to be generally concave. For instance, with particular reference to
[0040] If the curved interface surface 112 is configured or sized and shaped to replicate the surface of the patient's phalangeal proximal head, the second surface 114 may, for example, have an approximate minimum height of 0.09 inches, measured from the center point/lowest point of the curved interface surface 112 to the start of the first portion 160 of the fixation member 150. Further, the height of the highest point around the lip or edge where the lower curved edge 118 abuts the inner concave surface 122 may include a range, for example, of approximately 0.111 in.-0.210 in. to the start of the first portion 160 of the fixation member 150. For instance, if the implant 100 is configured or sized and shaped to replicate the surface of the patient's phalangeal proximal head, the total height of the implant, which includes both the fixation member 150 and the bearing member 110, may range, for example, from about 0.428 in. to about 0.528 in., based on the fixation member 150 having an approximate height of, for example, 0.318 in.
[0041] Although not shown, various other embodiments are also contemplated herein, which may include, for example, a non-cylindrical second surface 114 depending on a particular shape of the fixation member 150. For instance, the fixation member 150, according to one embodiment, may include a cross-sectional outer surface shape that is non-cylindrical such as, for example, a polygon, triangle, square, rectangle, pentagon, hexagon, heptagon, or octagon, which may facilitate anti-rotation of the implant once implanted into the patient's bone.
[0042] Additionally, the bearing member 110 may include a hydrophilic polymer, which may, for example, include hyaluronic acid and ultrahigh molecular weight polyethylene (UHMWPE). Other embodiments may include, for example, polyurethane, polyether ether ketone (PEEK), or a hydrogel. Further examples of suitable polymeric materials are described in U.S. Pat. No. 7,662,954, issued to James, et al. entitled “Outer Layer Having Entanglement Of Hydrophobic Polymer Host And Hydrophilic Polymer Guest,” which is incorporated herein by reference in its entirety. Advantageously, polymer combinations such as hyaluronic acid with UHMWPE may, for example, attract lubricating joint fluid to the bearing member 110, enabling the bearing member 110 to include self-lubricating properties. Also, other embodiments for the bearing member 110 may include, for example, metals such as cobalt chrome.
[0043] The fixation member 150 may include, according to one embodiment, at least one standard metallic biocompatible implant material such as, for example, titanium, cobalt chrome, or other acceptable stainless steels. The first portion 160 of the fixation member 150 may include various layers. For instance, the first portion 160 may include, for example, a first section 164 positioned between the bearing member 110 and the non-porous barrier 162. In one embodiment, the first section 164 may include, for example, a titanium-based porous material, which may include at least one void 166 capable of receiving the hydrophilic polymer during the manufacturing process. The first portion 160 may also include, for example, a second section that includes the non-porous barrier 162. Further, the first portion 160 may also include a third section 168 positioned between the non-porous barrier 162 and the tapered second portion 170. The third section 168 may also include, for example, additional titanium-based porous material, which may also include at least one void 166 capable of receiving bone ingrowth after implantation. The at least one void 166 may, for example, include an approximate average pore size of 523 microns and include an average interconnection size of approximately 229 microns. Further, the overall porosity of the first section 164, the third section 168 and the tapered second portion 170 may be, for example, approximately 60%,
[0044] Further, the tapered second portion 170 of the toe implant 100 may also include an angular surface 172 capable of preventing subsidence of the toe implant 100 into a patient's metatarsal bone. For instance, the angular surface 172 may be angled such that the tapered second portion 170 includes, for example, a first diameter D.sub.1 at the top 174 of the tapered second portion 170, and a second diameter D.sub.2 at the bottom 176 of the tapered second portion 170. Further, the second diameter D.sub.2 may be less than the first diameter D.sub.1 such that D.sub.2<D.sub.1. The angular surface 172 may include, for example, any angle capable of providing adequate resistance to prevent the implant 100 from subsiding into the patient's resected metatarsal head post-implantation. In particular, the angular surface 172 may be pressed into a patient's resected metatarsal such that the angular surface 172 engages the inner walls of the metatarsal bone to better secure the implant 100 to the metatarsal head. For instance, according to one embodiment, the angular surface 172 may be angled, for example, approximately 20 degrees inward from the first diameter D.sub.1 to the second diameter D.sub.2. In other embodiments, the angular surface 172 may include an angle that is, for example, larger or smaller depending on the diameter size of the fixation member 150. In various embodiments, the tapered second portion 170 may adjoin the non-porous barrier 162, such that the entire bottom portion of the implant 100 includes an angular surface 172. In other embodiments, the fixation member 150 may be comprised of a biocompatible non-metallic polymer such as, for example, polyether ether ketone (PEEK).
[0045] The fixation member 150 may include a total height H.sub.T that is a summation of a height H.sub.1 of the first portion 160 and a height H.sub.2 of the tapered second portion 170 such that H.sub.1+H.sub.2=H.sub.T. Various ratios and approximate distributions of the aggregate height of the cylindrical member 160 relative to the tapered second portion 170, may be possible including, for example, H.sub.1≈1.0 to 3.0×H.sub.2, or more particularly H.sub.1≈1.3 to 1.7×H.sub.2.
[0046] In one embodiment, the fixation member 150 may, for example, be non-porous and have a surface treatment for the angular surface 172 and/or other portions of the implant 100 to interact with the inner walls of the resected bone of the metatarsal head. The surface treatment may include, for example, a porous coating such as a hydroxyapatite (HA) coating, titanium plasma spray, or grit blasting, which may allow for a higher coefficient of friction to better fix the implant 100 in the resected metatarsal head and promote bone in growth. Further, the implant 100 may be affixed to the metatarsal distal head or phalangeal proximal head with, for example, a pin, stem, screw, bone cement, or a combination thereof in order to prevent movement, prevent the implant 100 from sliding out of the resected bone of either the metatarsal distal head or phalangeal proximal head, and facilitate bone in growth.
[0047] The toe implant 100 may be designed in multiple sizes to allow selection by a medical professional based on the width and/or depth of the particular metatarsal bone or phalangeal bone being treated. According to one embodiment, the total diameter of the implant 100 may be commensurate with the diameter of the first portion 160 of the implant 100. For an implant 100 that may be configured or sized and shaped to replicate the metatarsal distal head, the total diameter may be selected from a plurality of differently sizes based on normal surface anatomy of a patient's metatarsal distal head. Sizes may range, for example, between 6 mm and 14 mm, with measurements of example sizes 6 mm, 8 mm, 10 mm, 12 mm, and 14 mm shown in Table 1 below.
TABLE-US-00001 TABLE 1 Implant Diameter D.sub.1 (inches) D.sub.2 (inches) H.sub.I (inches) a) 6 mm 0.2367 0.195 0.411 b) 8 mm 0.3156 0.274 0.482 c) 10 mm 0.3912 0.350 0.498 d) 12 mm 0.4723 0.431 0.519 e) 14 mm 0.5512 0.510 0.544
[0048] As mentioned above, and with reference to Table 1, diameter D.sub.1 includes an approximate diameter at the top 174 of the tapered second portion 170, as well as the diameter of the first portion 160 of the fixation member 150, and diameter D.sub.2 includes an approximate diameter at the bottom 176 of the tapered second portion 170 of the implant 100. Further, height H.sub.1 represents the full height of the implant 100 from the center of the bearing member 110 at the highest point of the upper curved edge 116 to the bottom 176 of the tapered second portion 170.
[0049] For an implant 100 configured or sized and shaped to replicate the phalangeal proximal head, the total diameter may be selected from a plurality of different sizes based on normal surface anatomy of a patient's phalangeal proximal head. Example sizes may range between 10 mm and 20 mm, with measurements of example sizes 10 mm and 20 mm shown in Table 2 below.
TABLE-US-00002 TABLE 2 Implant Diameter D.sub.1 (inches) H.sub.I (inches) H.sub.BM (inches) a) 10 mm 0.392 0.429 0.111 b) 20 mm 0.787 0.528 0.210
[0050] With reference to Table 2, and as stated above, diameter D.sub.1 includes an approximate diameter at the top 174 of the tapered second portion 170, as well as the diameter of the first portion 160 of the fixation member 150. Further, height H.sub.1 represents the full height of the implant 100 from the highest point around the lip or edge where the lower curved edge 118 abuts the inner concave surface 122 to the bottom 176 of the tapered second portion 170. Additionally, height H.sub.BM represents the height of the bearing member 110 measured from the start of the first portion 160 of the fixation member 150 to the highest point around the lip or edge where the lower curved edge 118 abuts the inner concave surface 122.
[0051] In
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[0054] Referring now to
[0055] Referring now to
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[0057] In some embodiments, for each reamer 346 and/or at least one cutting flute 348 there would, for example, be a corresponding implant radius. Additionally, the kit of the present disclosure may include reusable tools or single use tools. In other embodiments, a reamer 346 and/or at least one flute 348 may be operably adjustable, e.g., to adjust the angle and/or the depth of the cut to be made, so as to be used with any number of implants that may be selected.
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[0060] The kit further includes a tamper 390, as seen in
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[0062] Also disclosed herein is a surgical method. Referring now to
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[0064] Molding, via a compression process, the polymer onto a top portion of the fixation member 504 may also include, for example, applying heat to the polymer and applying pressure to the polymer. This method of manufacture 500 may enable the polymer to flow in a controlled manner into any voids in the porous material of the top portion of the fixation member, and the polymer may stop flowing upon reaching the non-porous material.
[0065] As may be recognized by those of ordinary skill in the art based on the teachings herein, numerous changes and modifications may be made to the above-described and other embodiments of the present invention without departing from the scope of the invention. The implants, screws, and other components of the devices and/or apparatus as disclosed in the specification, including the accompanying abstract and drawings, may be replaced by alternative component(s) or feature(s), such as those disclosed in another embodiment, which serve the same, equivalent or similar purpose as known by those skilled in the art to achieve the same, equivalent or similar results by such alternative component(s) or feature(s) to provide a similar function for the intended purpose. In addition, the devices and apparatus may include more or fewer components or features than the embodiments as described and illustrated herein. Accordingly, this detailed description of the currently-preferred embodiments is to be taken as illustrative, as opposed to limiting the invention.
[0066] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprise” (and any form of comprise, such as “comprises” and “comprising”), “have” (and any form of have, such as “has”, and “having”), “include” (and any form of include, such as “includes” and “including”), and “contain” (and any form of contain, such as “contains” and “containing”) are open-ended linking verbs. As a result, a method or device that “comprises,” “has,” “includes,” or “contains” one or more steps or elements possesses those one or more steps or elements, but is not limited to possessing only those one or more steps or elements. Likewise, a step of a method or an element of a device that “comprises,” “has,” “includes,” or “contains” one or more features possesses those one or more features, but is not limited to possessing only those one or more features. Furthermore, a device or structure that is configured in a certain way is configured in at least that way, but may also be configured in ways that are not listed.
[0067] The invention has been described with reference to the preferred embodiments. It will be understood that the architectural and operational embodiments described herein are exemplary of a plurality of possible arrangements to provide the same general features, characteristics, and general apparatus operation. Modifications and alterations will occur to others upon a reading and understanding of the preceding detailed description. It is intended that the invention be construed as including all such modifications and alterations.